View source for Template:Element-symbol-to-oxidation-state-data

{{ {{{os-formatter|Element-symbol-to-oxidation-state-echo}}}
|symbol={{{symbol|}}}
|common={{#switch:{{{symbol|}}}
|H=−1, +1
|He=
|Li=+1
|Be=+2
|B=+3
|C=−4, −3, −2, −1, 0, +1, +2, +3, +4
|N=−3, +3, +5
|O=−2
|F=−1
|Ne=
|Na=+1
|Mg=+2
|Al=+3
|Si=−4, +4
|P=−3, +3, +5
|S=−2, +2, +4, +6
|Cl=−1, +1, +3, +5, +7
|Ar=
|K=+1
|Ca=+2
|Sc=+3
|Ti=+4
|V=+5
|Cr=+3, +6
|Mn=+2, +4, +7
|Fe=+2, +3
|Co=+2, +3
|Ni=+2
|Cu=+2
|Zn=+2
|Ga=+3
|Ge=−4, +2, +4
|As=−3, +3, +5
|Se=−2, +2, +4, +6
|Br=−1, +1, +3, +5
|Kr=+2
|Rb=+1
|Sr=+2
|Y=+3
|Zr=+4
|Nb=+5
|Mo=+4, +6
|Tc=+4, +7
|Ru=+3, +4
|Rh=+3
|Pd=0, +2, +4
|Ag=+1
|Cd=+2
|In=+3
|Sn=−4, +2, +4
|Sb=−3, +3, +5
|Te=−2, +2, +4, +6
|I=−1, +1, +3, +5, +7
|Xe=+2, +4, +6
|Cs=+1
|Ba=+2
|La=+3
|Ce=+3, +4
|Pr=+3
|Nd=+3
|Pm=+3
|Sm=+3
|Eu=+2, +3
|Gd=+3
|Tb=+3
|Dy=+3
|Ho=+3
|Er=+3
|Tm=+3
|Yb=+3
|Lu=+3
|Hf=+4
|Ta=+5
|W=+4, +6
|Re=+4, +7
|Os=+4
|Ir=+3, +4
|Pt=+2, +4
|Au=+3
|Hg=+1, +2
|Tl=+1, +3
|Pb=+2, +4
|Bi=+3
|Po=−2, +2, +4
|At=−1, +1
|Rn=
|Fr=+1
|Ra=+2
|Ac=+3
|Th=+4
|Pa=+5
|U=+6
|Np=+5
|Pu=+4
|Am=+3
|Cm=+3
|Bk=+3
|Cf=+3
|Es=+3
|Fm=+3
|Md=+3
|No=+3
|Lr=+3
|Rf=+4
|Db=<!-- no common, only predicted for the rest -->
|Sg=
|Bh=
|Hs=
|Mt=
|Ds=
|Rg=
|Cn=
|Nh=
|Fl=
|Mc=
|Lv=
|Ts=
|Og=
|Uue=
|Ubn=
|Ubu=
|Ubb=
|Ubt=
|Ubq=
|Ubp=
|Ubh=
<!--- default for symbol --->
|#default={{#if:{{{symbol|}}}|{{error|[[:Template:Infobox element/symbol-to-oxidation-state]]: Symbol "{{{symbol|}}}" not known}}}}
}}
|notable={{#switch:{{{symbol|}}}
<!--- Period 1 --->
| H= 
| He=0<ref>Disodium helide, (Na<sup>+</sup>)<sub>2</sub>He(e<sup>−</sup>)<sub>2</sub>, has been synthesized at high pressure, see {{cite journal |last1=Dong |first1=Xiao |last2=Oganov |first2=Artem R. |last3=Goncharov |first3=Alexander F. |last4=Stavrou |first4=Elissaios |last5=Lobanov |first5=Sergey |last6=Saleh |first6=Gabriele |last7=Qian |first7=Guang-Rui |last8=Zhu |first8=Qiang |last9=Gatti |first9=Carlo |last10=Deringer |first10=Volker L. |last11=Dronskowski |first11=Richard |last12=Zhou |first12=Xiang-Feng |last13=Prakapenka |first13=Vitali B. |last14=Konôpková |first14=Zuzana |last15=Popov |first15=Ivan A. |last16=Boldyrev |first16=Alexander I. |last17=Wang |first17=Hui-Tian |title=A stable compound of helium and sodium at high pressure |journal=[[Nature Chemistry]] |volume=9 |issue=5|pages=440–445 |date=6 February 2017 |doi=10.1038/nchem.2716 |pmid=28430195 |bibcode=2017NatCh...9..440D |arxiv=1309.3827 |s2cid=20459726}}</ref>
<!--- Period 2 --->
| Li= −1<ref>Li(–1) has been observed in the gas phase; see {{cite journal |author1=R. H. Sloane |author2=H. M. Love |title=Surface Formation of Lithium Negative Ions |journal=Nature |date=1947 |volume=159 |pages=302–303 |doi=10.1038/159302a0 |language=en}}</ref>
| Be= +1{{refn|Be(I) is known in CpBeBeCp.<ref name="BCWABe(I)">{{Cite journal |last1=Boronski |first1=Josef T. |last2=Crumpton |first2=Agamemnon E. |last3=Wales |first3=Lewis L. |last4=Aldridge |first4=Simon |date=2023-06-16 |title=Diberyllocene, a stable compound of Be(I) with a Be–Be bond |url=https://www.science.org/doi/10.1126/science.adh4419 |journal=Science |language=en |volume=380 |issue=6650 |pages=1147–1149 |doi=10.1126/science.adh4419 |pmid=37319227 |bibcode=2023Sci...380.1147B |s2cid=259166086 |issn=0036-8075}}</ref> While Be(0) is claimed to exist in bis(carbene) compounds,<ref name="Arrowsmith">{{Cite journal |last1=Arrowsmith |first1=Merle |last2=Braunschweig |first2=Holger |last3=Celik |first3=Mehmet Ali |last4=Dellermann |first4=Theresa |last5=Dewhurst |first5=Rian D. |last6=Ewing |first6=William C. |last7=Hammond |first7=Kai |last8=Kramer |first8=Thomas |last9=Krummenacher |first9=Ivo |title=Neutral zero-valent s-block complexes with strong multiple bonding |journal=Nature Chemistry |volume=8 |issue=9 |pages=890–894 |doi=10.1038/nchem.2542 |pmid=27334631 |bibcode=2016NatCh...8..890A |year=2016}}</ref> its existence has been questioned.<ref name="Gimferrer">{{Cite journal |last1=Gimferrer |first1=Martí |last2=Danés |first2=Sergi |last3=Vos |first3=Eva |last4=Yildiz |first4=Cem B. |last5=Corral |first5=Inés |last6=Jana |first6=Anukul |last7=Salvador |first7=Pedro |last8=Andrada |first8=Diego M. |date=2022-06-07 |title=The oxidation state in low-valent beryllium and magnesium compounds |journal=Chemical Science |language=en |volume=13 |issue=22 |pages=6583–6591 |doi=10.1039/D2SC01401G |issn=2041-6539 |pmc=9172369 |pmid=35756523}}</ref>}}
| B=−5,<ref>B(−5) has been observed in Al<sub>3</sub>BC, see {{cite news|url=https://d-nb.info/995006210/34|first1=Melanie|last1=Schroeder|title=Eigenschaften von borreichen Boriden und Scandium-Aluminium-Oxid-Carbiden|page=139|language=de}}</ref> −1,<ref>B(−1) has been observed in [[magnesium diboride]] (MgB<sub>2</sub>), see {{cite book|url=https://books.google.com/books?id=2RgbAgAAQBAJ&pg=PA315|title=Chemical Structure and Reactivity: An Integrated Approach|first1=James|last1=Keeler|first2=Peter|last2=Wothers|publisher=Oxford University Press|year=2014|isbn=9780199604135}}</ref> 0,<ref>{{cite journal|doi=10.1126/science.1221138|title=Ambient-Temperature Isolation of a Compound with a Boron-Boron Triple Bond|year=2012|last1=Braunschweig|first1=H.|last2=Dewhurst|first2=R. D. |last3=Hammond|first3=K.|last4=Mies|first4=J.|last5=Radacki|first5=K.|last6=Vargas|first6=A.|journal=Science|volume=336|issue=6087|pages=1420–2|pmid=22700924|bibcode=2012Sci...336.1420B|s2cid=206540959}}</ref> +1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref><ref>{{cite journal| url=http://bernath.uwaterloo.ca/media/125.pdf| title=Infrared Emission Spectroscopy of BF and AIF| author1=Zhang, K.Q.| author2=Guo, B.|author3=Braun, V.| author4=Dulick, M.| author5=Bernath, P.F.| journal=J. Molecular Spectroscopy| volume=170| issue=1| year=1995| page=82| doi=10.1006/jmsp.1995.1058|bibcode=1995JMoSp.170...82Z}}</ref> +2<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> 
| C=
| N=−2,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> −1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> 0,<ref>[[Tetrazole]]s contain a pair of double-bonded nitrogen atoms with oxidation state 0 in the ring. A Synthesis of the parent 1H-tetrazole, {{chem2|CH2N4}} (two atoms N(0)) is given in {{cite journal | last=Henry | first=Ronald A. | last2=Finnegan | first2=William G. | title=An Improved Procedure for the Deamination of 5-Aminotetrazole | journal=Journal of the American Chemical Society | volume=76 | issue=1 | date=1954 | issn=0002-7863 | doi=10.1021/ja01630a086 | pages=290–291}}</ref> +1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +2,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +4<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref>
| O= −1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> 0, +1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +2<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref>
| F=0<ref>Gold heptafluoride, synthesized at low temperature, is calculated to be a complex of molecular fluorine with gold pentafluoride, with F-F bonding in the F<sub>2</sub> evidenced by IR spectroscopy; see {{cite journal|title=After 20 Years, Theoretical Evidence That "AuF<sub>7</sub>" Is Actually AuF<sub>5</sub>·F<sub>2</sub>|journal=Inorganic Chemistry|date=2007-05-31|volume=46|issue=13|pages=5338–5342|doi=10.1021/ic700431s|last1=Himmel|first1=Daniel|last2=Riedel|first2=Sebastian|pmid=17511450}}</ref>
| Ne=0<ref>Ne(0) has been observed in Cr(CO)<sub>5</sub>Ne; see {{cite journal|last1=Perutz|first1=Robin N.|last2=Turner|first2=James J. |title=Photochemistry of the Group 6 hexacarbonyls in low-temperature matrices. III. Interaction of the pentacarbonyls with noble gases and other matrices|journal=Journal of the American Chemical Society|date=August 1975|volume=97|issue=17|pages=4791–4800 |doi=10.1021/ja00850a001}}</ref>
<!--- Period 3 --->
| Na=−1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> 0,<ref>The compound [[NaCl]] has been shown in experiments to exists in several unusual [[stoichiometry|stoichiometries]] under high pressure, including Na<sub>3</sub>Cl in which contains a layer of sodium(0) atoms; see {{Cite journal |last1=Zhang |first1=W. |last2=Oganov |first2=A. R. |last3=Goncharov |first3=A. F. |last4=Zhu |first4=Q. |last5=Boulfelfel |first5=S. E. |last6=Lyakhov |first6=A. O. |last7=Stavrou |first7=E. |last8=Somayazulu |first8=M. |last9=Prakapenka |first9=V. B. |last10=Konôpková |first10=Z. |year=2013 |title=Unexpected Stable Stoichiometries of Sodium Chlorides |journal=Science |volume=342 |issue=6165 |pages=1502–1505 |arxiv=1310.7674 |bibcode=2013Sci...342.1502Z |doi=10.1126/science.1244989 |pmid=24357316|s2cid=15298372}}</ref>  
| Mg= 0,<ref>Mg(0) has been synthesized in a compound containing a Na<sub>2</sub>Mg<sub>2</sub><sup>2+</sup> cluster coordinated to a bulky organic ligand; see {{cite journal |first1=B. |last1=Rösch |first2=T. X. |last2=Gentner |first3=J. |last3=Eyselein |first4=J. |last4=Langer |first5=H. |last5=Elsen |first6=W. |last6=Li |first7=S. |last7=Harder |title=Strongly reducing magnesium(0) complexes |doi=10.1038/s41586-021-03401-w |journal=Nature |volume=592 |year=2021 |issue=7856 |pages=717–721 |pmid=33911274 |bibcode=2021Natur.592..717R |s2cid=233447380 |postscript=none}}</ref> +1<ref>{{cite journal|url=http://bernath.uwaterloo.ca/media/24.pdf| title=The spectrum of magnesium hydride |author=Bernath, P. F. |author2=Black, J. H. |author3=Brault, J. W. |name-list-style=amp |bibcode=1985ApJ...298..375B | doi=10.1086/163620
|journal=Astrophysical Journal|volume=298| year=1985| page=375}}. See also [[Low valent magnesium compounds]].</ref>  
| Al=−2,<ref>Al(−2) has been observed in Sr<sub>14</sub>[Al<sub>4</sub>]<sub>2</sub>[Ge]<sub>3</sub>, see {{cite journal|last1=Wemdorff|first1=Marco|last2=Röhr|first2=Caroline|title=Sr<sub>14</sub>[Al<sub>4</sub>]<sub>2</sub>[Ge]<sub>3</sub>: Eine Zintl-Phase mit isolierten [Ge]<sup>4–</sup>- und [Al<sub>4</sub>]<sup>8–</sup>-Anionen / Sr<sub>14</sub>[Al<sub>4</sub>]<sub>2</sub>[Ge]<sub>3</sub>: A Zintl Phase with Isolated [Ge]<sup>4–</sup>- and [Al<sub>4</sub>]<sup>8–</sup> Anions|journal=Zeitschrift für Naturforschung B|language=de|volume=62|issue=10|year=2007|page=1227|doi=10.1515/znb-2007-1001|s2cid=94972243}}</ref> −1,<ref>Al(–1) has been reported in Na<sub>5</sub>Al<sub>5</sub>; see {{cite journal |author1=Haopeng Wang |author2=Xinxing Zhang |author3=Yeon Jae Ko |author4=Andrej Grubisic |author5=Xiang Li |author6=Gerd Ganteför |author7=Hansgeorg Schnöckel |author8=Bryan W. Eichhorn |author9=Mal-Soon Lee |author10=P. Jena |author11=Anil K. Kandalam |author12=Boggavarapu Kiran |author13=Kit H. Bowen |title=Aluminum Zintl anion moieties within sodium aluminum clusters |journal=The Journal of Chemical Physics |date=2014 |volume=140 |issue=5 |doi=10.1063/1.4862989 |language=en}}</ref> 0,<ref>Unstable carbonyl of Al(0) has been detected in reaction of [[Trimethylaluminum|Al<sub>2</sub>(CH<sub>3</sub>)<sub>6</sub>]] with carbon monoxide; see {{cite journal |first1=Ramiro |last1=Sanchez |first2=Caleb |last2=Arrington |first3=C. A. |last3=Arrington Jr. |title=Reaction of trimethylaluminum with carbon monoxide in low-temperature matrixes |journal=American Chemical Society |volume=111 |issue=25 |date=December 1, 1989 |page=9110-9111 |doi=10.1021/ja00207a023 |osti=6973516 |url=https://www.osti.gov/biblio/6973516-reaction-trimethylaluminum-carbon-monoxide-low-temperature-matrices}}</ref> +1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref><ref>{{cite journal| title = Aluminum(I) and Gallium(I) Compounds: Syntheses, Structures, and Reactions|author1=Dohmeier, C. |author2=Loos, D. |author3=Schnöckel, H. | journal = Angewandte Chemie International Edition | year =1996| volume =35|issue=2 | pages =129–149| doi =10.1002/anie.199601291}}</ref> +2<ref>{{cite journal| author = Tyte, D. C. | title = Red (B2Π–A2σ) Band System of Aluminium Monoxide| doi = 10.1038/202383a0 | journal = Nature | volume = 202| issue = 4930 | year = 1964| page = 383 | bibcode=1964Natur.202..383T| s2cid = 4163250}}</ref>  
| Si=−3,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> −2,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> −1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> 0,<ref name=ZeroValentTin>{{cite web |title=New Type of Zero-Valent Tin Compound |url= https://www.chemistryviews.org/details/news/9745121/New_Type_of_Zero-Valent_Tin_Compound.html |publisher=[[Chemistry Europe]] |date=27 August 2016}}</ref> +1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref><ref>{{cite journal|author=Ram, R. S.|title=Fourier Transform Emission Spectroscopy of the A2D–X2P Transition of SiH and SiD|url=http://bernath.uwaterloo.ca/media/184.pdf |journal=J. Mol. Spectr. |volume=190|issue=2|pages=341–352|year=1998|pmid=9668026|display-authors=etal|doi=10.1006/jmsp.1998.7582}}</ref> +2,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +3<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref>  
| P = −2,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> −1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> 0,<ref>{{cite journal|doi=10.1021/ja807828t|title=Carbene-Stabilized Diphosphorus|year=2008|last1=Wang|first1=Yuzhong|last2=Xie|first2=Yaoming|last3=Wei|first3=Pingrong|last4=King|first4=R. Bruce|last5=Schaefer|first5=Iii|last6=Schleyer|first6=Paul v. R.|last7=Robinson|first7=Gregory H.|journal=Journal of the American Chemical Society|volume=130|issue=45|pages=14970–1|pmid=18937460}}</ref> +1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref><ref>{{cite journal|doi=10.1021/ic060186o|pmid=16903744|title=Phosphorus(I) Iodide: A Versatile Metathesis Reagent for the Synthesis of Low Oxidation State Phosphorus Compounds|year=2006|last1=Ellis|first1=Bobby D.|last2=MacDonald|first2=Charles L. B.|journal=Inorganic Chemistry|volume=45|issue=17|pages=6864–74}}</ref> +2,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +4<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref>  
| S= −1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> 0, +1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +3,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +5<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref>  
| Cl= +2,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +4,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +6<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref>
| Ar=0<ref>Ar(0) has been observed in [[argon fluorohydride]] (HArF) and ArCF<sub>2</sub><sup>2+</sup>, see {{cite journal |display-authors=4 |last1=Lockyear|first1=J.F. |last2=Douglas|first2=K. |last3=Price|first3=S.D. |last4=Karwowska|first4=M. |last5=Fijalkowski|first5=K.J. |last6=Grochala|first6=W. |last7=Remeš|first7=M. |last8=Roithová|first8=J. |last9=Schroder|first9=D. |name-list-style=amp |date=2010 |title=Generation of the ArCF<sub>2</sub><sup>2+</sup> Dication |journal=[[Journal of Physical Chemistry Letters]] |volume=1 |page=358 |doi=10.1021/jz900274p}}</ref>
<!--- Period 4 --->
| K=−1<ref name="neg metals">{{cite journal |author1=John E. Ellis |title=Adventures with Substances Containing Metals in Negative Oxidation States |journal=Inorganic Chemistry |date=2006 |volume=45 |issue=8 |doi=10.1021/ic052110i |language=en}}</ref>
| Ca=+1<ref name="West">{{cite journal|last1=Krieck|first1=Sven|last2=Görls|first2=Helmar|last3=Westerhausen|first3=Matthias|title=Mechanistic Elucidation of the Formation of the Inverse Ca(I) Sandwich Complex [(thf)3Ca(μ-C6H3-1,3,5-Ph3)Ca(thf)3] and Stability of Aryl-Substituted Phenylcalcium Complexes|journal=Journal of the American Chemical Society|volume=132|issue=35|pages=12492–12501|year=2010|pmid=20718434|doi=10.1021/ja105534w}}</ref>  
| Sc= 0,<ref name="Cloke1991">{{cite journal |author=Cloke, F. Geoffrey N. |author2=Khan, Karl |author3=Perutz, Robin N. |name-list-style=amp |date=1991|title=η-Arene complexes of scandium(0) and scandium(II) |journal= J. Chem. Soc., Chem. Commun.|issue=19|pages=1372–1373|doi= 10.1039/C39910001372}}</ref> +1,<ref name="Smith">{{cite journal|title=Diatomic Hydride and Deuteride Spectra of the Second Row Transition Metals|first=R. E.|last=Smith | journal=Proceedings of the Royal Society of London. Series A, Mathematical and Physical Sciences|volume=332|pages=113–127|issue=1588|year=1973|doi=10.1098/rspa.1973.0015|bibcode=1973RSPSA.332..113S |s2cid=96908213}}</ref> +2<ref name="McGuire">{{cite journal|title=Preparation and Properties of Scandium Dihydride|first=Joseph C.|last=McGuire|author2=Kempter, Charles P.|journal=Journal of Chemical Physics|volume=33|issue=5|pages=1584–1585|year=1960|doi=10.1063/1.1731452|bibcode=1960JChPh..33.1584M }}</ref>  
| Ti=−2,<ref>Ti(-2) is known in {{chem2|Ti(CO)6(2-)}}; see {{cite journal |author1=John E. Ellis |title=Adventures with Substances Containing Metals in Negative Oxidation States |journal=Inorganic Chemistry |date=2006 |volume=45 |issue=8 |doi=10.1021/ic052110i |language=en}}</ref> −1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> 0,<ref>{{cite journal |last1= Jilek |first1= Robert E. |last2= Tripepi |first2= Giovanna |last3= Urnezius |first3= Eugenijus |last4= Brennessel |first4= William W. |last5= Young |first5= Victor G. Jr. |last6= Ellis |first6= John E. |title= Zerovalent titanium–sulfur complexes. Novel dithiocarbamato derivatives of {{awrap|Ti(CO)<sub>6</sub>:[Ti(CO)<sub>4</sub>(S<sub>2</sub>CNR<sub>2</sub>)]<sup>−</sup>}} |journal= Chem. Commun. |issue= 25 |year= 2007 |pages= 2639–2641 |doi= 10.1039/B700808B |pmid= 17579764}}</ref> +1,<ref>{{cite journal|author=Andersson, N.|title=Emission spectra of TiH and TiD near 938 nm|journal=J. Chem. Phys.|volume=118|issue=8|year=2003|page=10543|doi=10.1063/1.1539848|bibcode=2003JChPh.118.3543A |display-authors=etal}}</ref> +2,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +3<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref>
| V=−3,<ref>V(–3) is known in {{chem2|V(CO)5(3-)}}; see {{cite journal |author1=John E. Ellis |title=Adventures with Substances Containing Metals in Negative Oxidation States |journal=Inorganic Chemistry |date=2006 |volume=45 |issue=8 |doi=10.1021/ic052110i |language=en}}</ref> −1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> 0,<ref>V(0) is known in {{chem2|V(CO)6}}; see {{cite journal |author1=John E. Ellis |title=Adventures with Substances Containing Metals in Negative Oxidation States |journal=Inorganic Chemistry |date=2006 |volume=45 |issue=8 |doi=10.1021/ic052110i |language=en}}</ref> +1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +2,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +3,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +4<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref>
| Cr=−4,<ref>Cr(–4) is known in {{chem2|Na4Cr(CO)4}}; see {{cite journal |author1=John E. Ellis |title=Adventures with Substances Containing Metals in Negative Oxidation States |journal=Inorganic Chemistry |date=2006 |volume=45 |issue=8 |doi=10.1021/ic052110i |language=en}}</ref> −2,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> −1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> 0,<ref>Cr(0) is known in {{chem2|Cr(CO)6}}; see {{cite journal |author1=John E. Ellis |title=Adventures with Substances Containing Metals in Negative Oxidation States |journal=Inorganic Chemistry |date=2006 |volume=45 |issue=8 |doi=10.1021/ic052110i |language=en}}</ref> +1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +2,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +4,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +5<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref>
| Mn=−3,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> −2,<ref>Mn(–2) is known in {{chem2|Mn(cod)2(2-)}}; see {{cite journal |author1=John E. Ellis |title=Adventures with Substances Containing Metals in Negative Oxidation States |journal=Inorganic Chemistry |date=2006 |volume=45 |issue=8 |doi=10.1021/ic052110i |language=en}}</ref><ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref>  −1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> 0,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +3,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +5,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +6<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref>
| Fe=−2,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> −1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> 0,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +1,<ref>{{cite journal|last1=Ram |first1=R. S. |last2=Bernath |first2=P. F. |journal=Journal of Molecular Spectroscopy |volume=221| year=2003| page=261|bibcode=2003JMoSp.221..261R |doi=10.1016/S0022-2852(03)00225-X|title=Fourier transform emission spectroscopy of the g<sup>4</sup>Δ&ndash;a<sup>4</sup>Δ system of FeCl|issue=2}}</ref> +4,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +5,<ref>{{cite journal|doi=10.1002/zaac.19824910109|title=Recent developments in the field of high oxidation states of transition elements in oxides stabilization of six-coordinated Iron(V)|year=1982|last1=Demazeau|first1=G.|journal=Zeitschrift für anorganische und allgemeine Chemie|volume=491|pages=60–66|last2=Buffat|first2=B.|last3=Pouchard|first3=M.|last4=Hagenmuller|first4=P.}}</ref> +6,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +7<ref>{{cite journal|doi= 10.1039/C6CP06753K|pmid=27812577|title=Experimental and theoretical identification of the Fe(VII) oxidation state in FeO<sub>4</sub><sup>−</sup>|year=2016|last1=Lu|first1=J.|journal=Physical Chemistry Chemical Physics|volume=18|issue=45|pages=31125–31131|last2=Jian|first2=J.|last3=Huang|first3=W.|last4=Lin|first4=H.|last5=Li|first5=J|last6=Zhou|first6=M.|bibcode=2016PCCP...1831125L}}</ref> 
| Co=−3,<ref>Co(–3) is known in {{chem2|Na3Co(CO)3}}; see {{cite journal |author1=John E. Ellis |title=Adventures with Substances Containing Metals in Negative Oxidation States |journal=Inorganic Chemistry |date=2006 |volume=45 |issue=8 |doi=10.1021/ic052110i |language=en}}</ref> −1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> 0,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +4,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +5<ref name=greenwood>{{Greenwood&Earnshaw2nd|pages=1117–1119}}</ref> 
| Ni=−2,<ref>Ni(–2) is known in {{chem2|Ni(COD)2(2-)}}; see {{cite journal |author1=John E. Ellis |title=Adventures with Substances Containing Metals in Negative Oxidation States |journal=Inorganic Chemistry |date=2006 |volume=45 |issue=8 |doi=10.1021/ic052110i |language=en}}</ref> −1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> 0,<ref>Ni(0) is known in {{chem2|Ni(CO)4}}; see {{cite journal |author1=John E. Ellis |title=Adventures with Substances Containing Metals in Negative Oxidation States |journal=Inorganic Chemistry |date=2006 |volume=45 |issue=8 |doi=10.1021/ic052110i |language=en}}</ref> +1,<ref>{{cite journal| title=A Dinuclear Nickel(I) Dinitrogen Complex and its Reduction in Single-Electron Steps| journal=Angewandte Chemie International Edition| year=2009| volume=48 | issue=18| pages=3357–61| doi=10.1002/anie.200805862| last1=Pfirrmann| first1=Stefan| last2=Limberg| first2=Christian| last3=Herwig| first3=Christian| last4=Stößer| first4=Reinhard| last5=Ziemer| first5=Burkhard| pmid=19322853}}</ref> +3,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +4<ref>{{cite journal| title=A Stable Tetraalkyl Complex of Nickel(IV)| journal=Angewandte Chemie International Edition| year=2009| volume=48 | issue=2| pages=290–4| doi=10.1002/anie.200804435| last1=Carnes| first1=Matthew| last2=Buccella| first2=Daniela| last3=Chen| first3=Judy Y.-C.| last4=Ramirez| first4=Arthur P.| last5=Turro| first5=Nicholas J.| last6=Nuckolls| first6=Colin| last7=Steigerwald| first7=Michael| pmid=19021174}}</ref> 
| Cu=−2,<ref> Cu(−2) have been observed as dimeric anions [Cu<sub>4</sub>]<sup>2–</sup> in La<sub>2</sub>Cu<sub>2</sub>In; see {{cite journal|title=Late transition metal anions acting as p-metal elements|year=2008|author1=Changhoon Lee|author2=Myung-Hwan Whangbo|volume=10|issue=4|pages=444–449|journal=Solid State Sciences|doi=10.1016/j.solidstatesciences.2007.12.001|bibcode=2008SSSci..10..444K}}</ref> −1,<ref>{{cite journal|last=Jackson|first=Ross A.|last2=Evans|first2=Nicholas J.|last3=Babula|first3=Dawid J.|last4=Horsley Downie|first4=Thomas M.|last5=Charman|first5=Rex S. C.|last6=Neale|first6=Samuel E.|last7=Mahon|first7=Mary F.|last8=Liptrot|first8=David J.|title=Nucleophilicity at copper(-I) in a compound with a Cu–Mg bond|journal=Nature Communications|volume=16|issue=1|date=2025-01-28|issn=2041-1723|pmid=39875432|pmc=11775243|doi=10.1038/s41467-025-56544-z|doi-access=free}}</ref>  0,<ref>{{cite journal|first1=Marc-Etienne|last1=Moret|first2=Limei|last2=Zhang|first3=Jonas C.|last3=Peters|title=A Polar Copper–Boron One-Electron σ-Bond|journal=J. Am. Chem. Soc|year=2013|volume=135|issue=10|pages=3792–3795|doi=10.1021/ja4006578|pmid=23418750|url=https://authors.library.caltech.edu/37931/ }}</ref> +1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +3,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +4<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref>
| Zn=−2,<ref> Zn(−2) have been observed (as dimeric and monomeric anions; dimeric ions were initially reported to be [T–T]<sup>2−</sup>, but later shown to be [T–T]<sup>4−</sup> for all these elements) in Ca<sub>5</sub>Zn<sub>3</sub> (structure (AE<sup>2+</sup>)<sub>5</sub>(T–T)<sup>4−</sup>T<sup>2−</sup>⋅4e<sup>−</sup>); see {{cite journal|title=Late transition metal anions acting as p-metal elements|year=2008|author1=Changhoon Lee|author2=Myung-Hwan Whangbo|volume=10|issue=4|pages=444–449|journal=Solid State Sciences|doi=10.1016/j.solidstatesciences.2007.12.001|bibcode=2008SSSci..10..444K}} and {{cite journal|doi=10.1002/zaac.200900421|title=Analysis of Electronic Structures and Chemical Bonding of Metal-rich Compounds. 2. Presence of Dimer (T–T)<sup>4–</sup> and Isolated T<sup>2–</sup> Anions in the Polar Intermetallic Cr<sub>5</sub>B<sub>3</sub>-Type Compounds AE<sub>5</sub>T<sub>3</sub> (AE = Ca, Sr; T = Au, Ag, Hg, Cd, Zn)|year=2010|author1=Changhoon Lee|author2=Myung-Hwan Whangbo|author3=Jürgen Köhler|volume=636|issue=1|pages=36–40|journal=Zeitschrift für Anorganische und Allgemeine Chemie}}</ref> 0,<sup>?</sup> +1<ref>Zn(I) has been reported in [[decamethyldizincocene]]; see {{cite journal |author1=Resa, I. |author2=Carmona, E. |author3=Gutierrez-Puebla, E. |author4=Monge, A. | title = Decamethyldizincocene, a Stable Compound of Zn(I) with a Zn-Zn Bond | journal = [[Science (journal)|Science]] | doi = 10.1126/science.1101356 | pmid = 15326350 | year = 2004 | volume = 305 | issue = 5687 | pages = 1136–8|bibcode=2004Sci...305.1136R |s2cid=38990338 }}</ref>  
| Ga=−5,<ref name="Colture">{{cite thesis|url=http://www.uni-kassel.de/upress/online/frei/978-3-7281-2597-2.volltext.frei.pdf|author=Hofmann, Patrick |title=Colture. Ein Programm zur interaktiven Visualisierung von Festkörperstrukturen sowie Synthese, Struktur und Eigenschaften von binären und ternären Alkali- und Erdalkalimetallgalliden|page=72|language=de|date=1997|publisher=PhD Thesis, ETH Zurich|doi=10.3929/ethz-a-001859893|hdl=20.500.11850/143357 |isbn=978-3728125972}}</ref> −4,<ref name="Colture"/> −3,<ref>Ga(−3) has been observed in LaGa, see {{cite journal|lang=de|first1=Ines|last1=Dürr|first2=Britta|last2=Bauer|first3=Caroline|last3=Röhr|title=Lanthan-Triel/Tetrel-ide La(Al,Ga)<sub>''x''</sub>(Si,Ge)<sub>1-''x''</sub>. Experimentelle und theoretische Studien zur Stabilität intermetallischer 1:1-Phasen|journal=Z. Naturforsch.|year=2011|volume=66b|pages=1107–1121|url=http://www.znaturforsch.com/s66b/s66b1107.pdf}}</ref> −2,<ref name="Colture"/> −1,<ref>Ga(−1) has been observed in LiGa; see {{cite book|publisher=Walter de Gruyter|year=2008|edition=102| pages=1185|isbn=9783110206845|title=Lehrbuch der Anorganischen Chemie|first=Arnold F.|last=Holleman |author2=Wiberg, Egon |author3=Wiberg, Nils|language=de}}</ref> 0,<ref>Ga(0) is known in [[gallium monoiodide]]; see {{Cite journal|last1=Widdifield|first1=Cory M.|last2=Jurca|first2=Titel|last3=Richeson|first3=Darrin S.|last4=Bryce|first4=David L.|date=2012-03-16|title=Using 69/71Ga solid-state NMR and 127I NQR as probes to elucidate the composition of "GaI"|url=http://www.sciencedirect.com/science/article/pii/S0277538712000101|journal=Polyhedron|language=en|volume=35|issue=1|pages=96–100|doi=10.1016/j.poly.2012.01.003|issn=0277-5387}}</ref> +1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +2<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> 
| Ge=−3,<ref name="germanides">Ge(−1), Ge(−2), Ge(−3), and Ge(–4) have been observed in [[germanide]]s; see {{cite book|publisher=Walter de Gruyter|year=1995|edition=101| pages=953–959|isbn=978-3-11-012641-9|title=Lehrbuch der Anorganischen Chemie|first=Arnold F.|last=Holleman |author2=Wiberg, Egon |author3=Wiberg, Nils|language=de|chapter=Germanium}}</ref> −2,<ref name="germanides">Ge(−1), Ge(−2), Ge(−3), and Ge(–4) have been observed in [[germanide]]s; see {{cite book|publisher=Walter de Gruyter|year=1995|edition=101| pages=953–959|isbn=978-3-11-012641-9|title=Lehrbuch der Anorganischen Chemie|first=Arnold F.|last=Holleman |author2=Wiberg, Egon |author3=Wiberg, Nils|language=de|chapter=Germanium}}</ref> −1,<ref name="germanides">Ge(−1), Ge(−2), Ge(−3), and Ge(–4) have been observed in [[germanide]]s; see {{cite book|publisher=Walter de Gruyter|year=1995|edition=101| pages=953–959|isbn=978-3-11-012641-9|title=Lehrbuch der Anorganischen Chemie|first=Arnold F.|last=Holleman |author2=Wiberg, Egon |author3=Wiberg, Nils|language=de|chapter=Germanium}}</ref> 0,<ref name=ZeroValentTin2>{{cite web |title=New Type of Zero-Valent Tin Compound |url= https://www.chemistryviews.org/details/news/9745121/New_Type_of_Zero-Valent_Tin_Compound.html |publisher=[[Chemistry Europe]] |date=27 August 2016}}</ref> +1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +3<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref>  
| As=−2,<ref>As(−2) has been observed in CaAs; see {{cite book|publisher=Walter de Gruyter|year=2008|edition=102| pages=829|isbn=9783110206845|title=Lehrbuch der Anorganischen Chemie|first=Arnold F.|last=Holleman |author2=Wiberg, Egon |author3=Wiberg, Nils|language=de}}</ref> −1,<ref>As(−1) has been observed in LiAs; see {{cite journal |author1=Reinhard Nesper |title=Structure and chemical bonding in zintl-phases containing lithium |journal=Progress in Solid State Chemistry |date=1990 |issue=1 |pages=1-45 |doi=10.1016/0079-6786(90)90006-2 |language=en}}</ref> 0,<ref>{{cite journal|doi=10.1002/chem.200902840|title=Carbene Stabilization of Diarsenic: From Hypervalency to Allotropy|year=2010|last1=Abraham|first1=Mariham Y.|last2=Wang|first2=Yuzhong|last3=Xie|first3=Yaoming|last4=Wei|first4=Pingrong|last5=Shaefer III|first5=Henry F.|last6=Schleyer|first6=P. von R.|last7=Robinson|first7=Gregory H.|journal=Chemistry: A European Journal|volume=16|issue=2|pages=432–5|pmid=19937872}}</ref> +1,<ref>{{cite journal|doi=10.1021/ic049281s|pmid=15360247|title=Stabilized Arsenic(I) Iodide: A Ready Source of Arsenic Iodide Fragments and a Useful Reagent for the Generation of Clusters|year=2004|last1=Ellis|first1=Bobby D.|last2=MacDonald|first2=Charles L. B.|journal=Inorganic Chemistry|volume=43|issue=19|pages=5981–6}}</ref> +2,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +4<ref>As(IV) has been observed in [[arsenic(IV) hydroxide]] (As(OH)<sub>4</sub>) and {{chem2|HAsO-}}; see {{cite journal|doi=10.1021/ic00313a007|title=Arsenic(IV). A pulse-radiolysis study|year=1989|last1=Kläning|first1=Ulrik K.|last2=Bielski|first2=Benon H. J.|last3=Sehested|first3=K.|journal=Inorganic Chemistry|volume=28|issue=14|pages=2717–24}}</ref>
| Se=−1,<ref>Se(−1) has been observed in diselenides({{chem2|Se2(2-)}}, such as [[disodium diselenide]] (Na<sub>2</sub>Se<sub>2</sub>); see {{cite book|publisher=Walter de Gruyter|year=2008|edition=102| pages=829|isbn=9783110206845|title=Lehrbuch der Anorganischen Chemie|first=Arnold F.|last=Holleman |author2=Wiberg, Egon |author3=Wiberg, Nils|language=de}} and {{cite journal |author1=H. Föppl |author2=E. Busmann |author3=F.-K. Frorath |title=Die Kristallstrukturen von α-Na2S2 und K2S2, β-Na2S2 und Na2Se2 |journal=Zeitschrift für anorganische und allgemeine Chemie |date=1962 |volume=314 |issue=1 |pages=12-20 |doi=10.1002/zaac.19623140104 |language=de}}</ref> 0,<ref>A Se(0) atom has been identified using DFT in [ReOSe(2-pySe)<sub>3</sub>]; see {{cite journal|doi=10.1016/j.inoche.2014.04.003|title=Synthesis and structure of [ReOSe(2-Se-py)3]: A rhenium(V) complex with selenium(0) as a ligand|year=2014|last1=Cargnelutti|first1=Roberta|last2=Lang|first2=Ernesto S.|last3=Piquini|first3=Paulo|last4=Abram|first4=Ulrich|journal=Inorganic Chemistry Communications|volume=45|pages=48–50|issn=1387-7003}}</ref> +1,<ref>{{Greenwood&Earnshaw}}</ref> +3,<ref>Se(III) has been observed in Se<sub>2</sub>NBr<sub>3</sub>; see {{cite journal|title=Se<sub>2</sub>NBr<sub>3</sub>, Se<sub>2</sub>NCl<sub>5</sub>, Se<sub>2</sub>NCl<sup>−</sup><sub>6</sub>: New Nitride Halides of Selenium(III) and Selenium(IV)| volume= 2|issue= 11|pages=1393–1396|year=1996|doi=10.1002/chem.19960021108|last1=Lau|first1=Carsten|last2=Neumüller|first2=Bernhard|last3=Vyboishchikov|first3=Sergei F.|last4=Frenking|first4=Gernot|last5=Dehnicke|first5=Kurt|last6=Hiller|first6=Wolfgang|last7=Herker|first7=Martin|journal=Chemistry: A European Journal}}</ref> +5<sup>?</sup>  
| Br= +2,<ref>Br(II) is known to occur in bromine monoxide [[Radical (chemistry)|radical]]; see [https://pubs.acs.org/doi/10.1021/j100382a032 Kinetics of the bromine monoxide radical + bromine monoxide radical reaction]</ref> +4,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +7<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> 
| Kr=+1,<sup>?</sup>
<!--- Period 5 --->
| Rb=−1<ref>Rb(–1) is known in [[rubidides]]; see {{cite journal |author1=John E. Ellis |title=Adventures with Substances Containing Metals in Negative Oxidation States |journal=Inorganic Chemistry |date=2006 |volume=45 |issue=8 |doi=10.1021/ic052110i |language=en}}</ref>
| Sr=+1<ref>{{cite journal|url=http://bernath.uwaterloo.ca/media/149.pdf|title=High-Resolution Infrared Emission Spectrum of Strontium Monofluoride|journal=J. Molecular Spectroscopy| volume=175|issue=1|page=158|year=1996|doi=10.1006/jmsp.1996.0019|bibcode=1996JMoSp.175..158C|last1=Colarusso|first1=P.|last2=Guo|first2=B.|last3=Zhang|first3=K.-Q.|last4=Bernath|first4=P. F. }}</ref>  
| Y= 0,<ref name="Cloke1993">Yttrium and all lanthanides except Ce and Pm have been observed in the oxidation state 0 in bis(1,3,5-tri-t-butylbenzene) complexes, see {{cite journal |journal=Chem. Soc. Rev. |date=1993 |volume=22 |pages=17–24 |first=F. Geoffrey N. |last=Cloke |title=Zero Oxidation State Compounds of Scandium, Yttrium, and the Lanthanides |doi=10.1039/CS9932200017}} and {{cite journal|last1=Arnold|first1=Polly L.|last2=Petrukhina|first2=Marina A.|last3=Bochenkov|first3=Vladimir E.|last4=Shabatina|first4=Tatyana I.|last5=Zagorskii|first5=Vyacheslav V.|last6=Cloke|first9=F. Geoffrey N.|date=2003-12-15|title=Arene complexation of Sm, Eu, Tm and Yb atoms: a variable temperature spectroscopic investigation|journal=Journal of Organometallic Chemistry|volume=688|issue=1–2|pages=49–55|doi=10.1016/j.jorganchem.2003.08.028}}</ref> +1,<sup>?</sup> +2<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref>  
| Zr=−2,<ref>Zr(–2) is known in {{chem2|Zr(CO)6(2-)}}; see {{cite journal |author1=John E. Ellis |title=Adventures with Substances Containing Metals in Negative Oxidation States |journal=Inorganic Chemistry |date=2006 |volume=45 |issue=8 |doi=10.1021/ic052110i |language=en}}</ref> 0,<ref>Zr(0) occur in (η<sup>6</sup>-(1,3,5-<sup>''t''</sup>Bu)<sub>3</sub>C<sub>6</sub>H<sub>3</sub>)<sub>2</sub>Zr and [(η<sup>5</sup>-C<sub>5</sub>R<sub>5</sub>Zr(CO)<sub>4</sub>]<sup>−</sup>, see {{cite book|publisher=Elsevier Ltd.|year=2007|volume=4|pages=697–739|doi=10.1016/B0-08-045047-4/00062-5|title=Comprehensive Organometallic Chemistry III. From Fundamentals to Applications|first=P. J.|last=Chirik |author2=Bradley, C. A. |chapter=4.06 - Complexes of Zirconium and Hafnium in Oxidation States 0 to ii|isbn=9780080450476}}</ref> +1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +2,<ref name="Calderazzo">{{Cite journal |last=Calderazzo |first=Fausto |last2=Pampaloni |first2=Guido |date=January 1992 |title=Organometallics of groups 4 and 5: Oxidation states II and lower |url=https://linkinghub.elsevier.com/retrieve/pii/0022328X92831263 |journal=Journal of Organometallic Chemistry |language=en |volume=423 |issue=3 |pages=307–328 |doi=10.1016/0022-328X(92)83126-3}}</ref><ref name="Ma">{{Cite journal |last1=Ma |first1=Wen |last2=Herbert |first2=F. William |last3=Senanayake |first3=Sanjaya D. |last4=Yildiz |first4=Bilge |date=2015-03-09 |title=Non-equilibrium oxidation states of zirconium during early stages of metal oxidation |url=https://pubs.aip.org/apl/article/106/10/101603/236409/Non-equilibrium-oxidation-states-of-zirconium |journal=Applied Physics Letters |language=en |volume=106 |issue=10 |doi=10.1063/1.4914180 |bibcode=2015ApPhL.106j1603M |issn=0003-6951|hdl=1721.1/104888 |hdl-access=free }}</ref> +3<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref>
| Nb= −3,<ref>Nb(–3) occurs in {{chem2|Cs3Nb(CO)<sub>5</sub>}}; see {{cite journal |author1=John E. Ellis |title=Metal Carbonyl Anions:  from [Fe(CO)<sub>4</sub>]<sub>2</sub><sup>−</sup> to [Hf(CO)<sub>6</sub>]<sub>2</sub><sup>−</sup> and Beyond† |journal=Organometallics |date=2003 |volume=22 |issue=17 |pages=3322–3338 |doi=10.1021/om030105l |language=en}}</ref> −1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> 0,<ref name="lehrbuch">Nb(0) and Nb(I) has been observed in Nb(bpy)<sub>3</sub> and CpNb(CO)<sub>4</sub>, respectively; see {{cite book|publisher=Walter de Gruyter|year=2008|edition=102| pages=1554|isbn=9783110206845|title=Lehrbuch der Anorganischen Chemie|first=Arnold F.|last=Holleman |author2=Wiberg, Egon |author3=Wiberg, Nils|language=de}}</ref> +1,<ref name="lehrbuch">Nb(0) and Nb(I) has been observed in Nb(bpy)<sub>3</sub> and CpNb(CO)<sub>4</sub>, respectively; see {{cite book|publisher=Walter de Gruyter|year=2008|edition=102| pages=1554|isbn=9783110206845|title=Lehrbuch der Anorganischen Chemie|first=Arnold F.|last=Holleman |author2=Wiberg, Egon |author3=Wiberg, Nils|language=de}}</ref> +2,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +3,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +4<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> 
| Mo= −4,<ref>Mo(–4) occurs in {{chem2|Na4Mo(CO)<sub>4</sub>}}; see {{cite journal |author1=John E. Ellis |title=Metal Carbonyl Anions:  from [Fe(CO)<sub>4</sub>]<sub>2</sub><sup>−</sup> to [Hf(CO)<sub>6</sub>]<sub>2</sub><sup>−</sup> and Beyond† |journal=Organometallics |date=2003 |volume=22 |issue=17 |pages=3322–3338 |doi=10.1021/om030105l |language=en}}</ref> −2,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> −1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> 0,<ref>Mo(0) occurs in [[molybdenum hexacarbonyl]]; see {{cite journal |author1=John E. Ellis |title=Metal Carbonyl Anions:  from [Fe(CO)<sub>4</sub>]<sub>2</sub><sup>−</sup> to [Hf(CO)<sub>6</sub>]<sub>2</sub><sup>−</sup> and Beyond† |journal=Organometallics |date=2003 |volume=22 |issue=17 |pages=3322–3338 |doi=10.1021/om030105l |language=en}}</ref> +1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +2,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +3,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +5<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref>
| Tc= −1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +2,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +3,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +5,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +6<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref>
| Ru= −2,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref>  0,<ref>Ru(0) is present in the carbonyl-phosphine complex Ru(CO)<sub>2</sub>(PPh<sub>3</sub>)<sub>3</sub>, see {{cite journal | author = Stephane Sentets, Maria del Carmen Rodriguez Martinez, Laure Vendier, Bruno Donnadieu, Vincent Huc, Noël Lugan, and Guy Lavigne | title = Instant "Base-Promoted" Generation of Roper's-type Ru(0) Complexes Ru(CO)<sub>2</sub>(PR<sub>3</sub>)<sub>3</sub> from a Simple Carbonylchlororuthenium(II) Precursor | year = 2005 | journal = [[Journal of the American Chemical Society|J. Am. Chem. Soc.]] | volume = 127 | issue = 42 | pages = 14554–14555 | doi = 10.1021/ja055066e | pmid = 16231891 }}</ref> +1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +2,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +5,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +6,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +7,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +8<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> 
| Rh= −3,<ref>Ellis J E. Highly Reduced Metal Carbonyl Anions: Synthesis, Characterization, and Chemical Properties. Adv. Organomet. Chem, 1990, 31: 1-51.</ref> −1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> 0,<ref>{{Greenwood&Earnshaw2nd|page=1140}}</ref> +1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +2,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +4,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +5,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +6,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +7<ref>Rh(VII) is known in the RhO<sub>3</sub><sup>+</sup> cation, see {{cite journal |title=The Highest Oxidation State of Rhodium: Rhodium(VII) in [RhO3]+ |journal=Angew. Chem. Int. Ed. |date=2022 |doi=10.1002/anie.202207688|last1=Da Silva Santos |first1=Mayara |last2=Stüker |first2=Tony |last3=Flach |first3=Max |last4=Ablyasova |first4=Olesya S. |last5=Timm |first5=Martin |last6=von Issendorff |first6=Bernd |last7=Hirsch |first7=Konstantin |last8=Zamudio‐Bayer |first8=Vicente |last9=Riedel |first9=Sebastian |last10=Lau |first10=J. Tobias |volume=61 |issue=38 |pages=e202207688 |pmid=35818987 |pmc=9544489 }}</ref> 
| Pd= +1,<ref>Pd(I) is known in [Pd<sub>2</sub>]<sup>2+</sup> compounds; see {{cite journal |author1=Christoph Fricke |author2=Theresa Sperger |author3=Marvin Mendel |author4=Franziska Schoenebeck |title=Catalysis with Palladium(I) Dimers |journal=Angewandte Chemie International Edition |date=2020 |volume=60 |issue=7 |doi=10.1002/anie.202011825 |language=en}}</ref> +3,<ref>Pd(III) has been observed; see {{cite book|last1=Powers |first1=D. C. |last2=Ritter |first2=T. |title=Higher Oxidation State Organopalladium and Platinum Chemistry |chapter=Palladium(III) in Synthesis and Catalysis |volume=35 |pages=129–156 |date=2011 |doi=10.1007/978-3-642-17429-2_6 |pmid=21461129 |chapter-url=http://www.chem.harvard.edu/groups/ritter/pdf/2011-129t.pdf |series=Topics in Organometallic Chemistry |isbn=978-3-642-17428-5 |url-status=dead |archive-url=https://web.archive.org/web/20130612065217/http://www.chem.harvard.edu/groups/ritter/pdf/2011-129t.pdf |archive-date=June 12, 2013 |pmc=3066514|bibcode=2011hoso.book..129P }}</ref> +5<ref>Palladium(V) has been identified in complexes with organosilicon compounds containing pentacoordinate palladium; see {{cite journal |first1=Shigeru |last1=Shimada |first2=Yong-Hua |last2=Li |first3=Yoong-Kee |last3=Choe |first4=Masato |last4=Tanaka |first5=Ming |last5=Bao |first6=Tadafumi |last6=Uchimaru |title=Multinuclear palladium compounds containing palladium centers ligated by five silicon atoms |doi=10.1073/pnas.0700450104 |journal=Proceedings of the National Academy of Sciences |volume=104 |year=2007 |issue=19 |pages=7758–7763|pmid=17470819 |pmc=1876520 |doi-access=free }}</ref> 
| Ag= −2,<ref>Ag(−2) have been observed as dimeric and monomeric anions in Ca<sub>5</sub>Ag<sub>3</sub>, (structure (Ca<sup>2+</sup>)<sub>5</sub>(Ag–Ag)<sup>4−</sup>Ag<sup>2−</sup>⋅4e<sup>−</sup>); see {{cite journal|doi=10.1002/zaac.200900421|title=Analysis of Electronic Structures and Chemical Bonding of Metal-rich Compounds. 2. Presence of Dimer (T–T)<sup>4–</sup> and Isolated T<sup>2–</sup> Anions in the Polar Intermetallic Cr<sub>5</sub>B<sub>3</sub>-Type Compounds AE<sub>5</sub>T<sub>3</sub> (AE = Ca, Sr; T = Au, Ag, Hg, Cd, Zn)|year=2010|author1=Changhoon Lee|author2=Myung-Hwan Whangbo|author3=Jürgen Köhler|volume=636|issue=1|pages=36–40|journal=Zeitschrift für Anorganische und Allgemeine Chemie}}</ref> −1,<ref>The Ag<sup>−</sup> ion has been observed in metal ammonia solutions: see {{cite journal|doi=10.1021/ic000333x|title=Metal Ammonia Solutions: Solutions Containing Argentide Ions|year=2001|last1=Tran|first1=N. E.|last2=Lagowski|first2=J. J.|journal=Inorganic Chemistry|volume=40|issue=5|pages=1067–68}}</ref> 0,<ref>Ag(0) has been observed in carbonyl complexes in low-temperature matrices: see {{cite journal|doi=10.1021/ja00427a018|title=Synthesis using metal vapors. Silver carbonyls. Matrix infrared, ultraviolet-visible, and electron spin resonance spectra, structures, and bonding of silver tricarbonyl, silver dicarbonyl, silver monocarbonyl, and disilver hexacarbonyl|year=1976|last1=McIntosh|first1=D.|last2=Ozin|first2=G. A.|journal=J. Am. Chem. Soc.|volume=98|issue=11|pages=3167–75}}</ref> +2,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +3<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref>
| Cd= −2,<ref name="MetalAnions">Cd(−2) have been observed (as dimeric and monomeric anions; dimeric ions were initially reported to be [T–T]<sup>2−</sup>, but later shown to be [T–T]<sup>4−</sup>) in  Sr<sub>5</sub>Cd<sub>3</sub>; see {{cite journal|doi=10.1002/zaac.200900421|title=Analysis of Electronic Structures and Chemical Bonding of Metal-rich Compounds. 2. Presence of Dimer (T–T)<sup>4–</sup> and Isolated T<sup>2–</sup> Anions in the Polar Intermetallic Cr<sub>5</sub>B<sub>3</sub>-Type Compounds AE<sub>5</sub>T<sub>3</sub> (AE = Ca, Sr; T = Au, Ag, Hg, Cd, Zn)|year=2010|author1=Changhoon Lee|author2=Myung-Hwan Whangbo|author3=Jürgen Köhler|volume=636|issue=1|pages=36–40|journal=Zeitschrift für Anorganische und Allgemeine Chemie}}</ref> +1<ref>Cd(I) has been observed in [[cadmium(I) tetrachloroaluminate]] (Cd<sub>2</sub>(AlCl<sub>4</sub>)<sub>2</sub>); see {{cite book|publisher= Walter de Gruyter|year= 1985|edition= 91–100|pages= 1056–1057|isbn= 978-3-11-007511-3|title= Lehrbuch der Anorganischen Chemie|last1= Holleman|first1= Arnold F.|last2= Wiberg|first2=Egon |last3=Wiberg |first3=Nils |language= de|chapter= Cadmium}}</ref>  
| In= −5,<ref>{{cite journal|doi=10.1021/ic951378e|title=Synthesis, Structure, and Bonding of Two Lanthanum Indium Germanides with Novel Structures and Properties|year=1996|last1=Guloy|first1=A. M.|last2=Corbett|first2=J. D.|journal=Inorganic Chemistry|volume=35|issue=9|pages=2616–22|pmid=11666477}}</ref> −2,<ref>In(−2) has been observed in Na<sub>2</sub>In, see [https://books.google.com/books?id=v-04Kn758yIC&pg=PA69&lpg=PA69&dq=zintl+anions+Na2In&source=bl&ots=aXLYIpkfYq&sig=Mqh8WdnvGOt2J2OPVLNqn79YVyk&hl=ru&sa=X&ei=XNDkVNeSJeXOyQOb8oBA&ved=0CBsQ6AEwADgK#v=onepage&q&f=false], p. 69.</ref> −1,<ref>In(−1) has been observed in NaIn; see {{cite book|publisher=Walter de Gruyter|year=2008|edition=102|page=1185|isbn=9783110206845|title=Lehrbuch der Anorganischen Chemie|first=Arnold F.|last=Holleman |author2=Wiberg, Egon |author3=Wiberg, Nils|language=de}}</ref> 0,<ref>Unstable In(0) carbonyls and clusters have been detected, see [https://www.researchgate.net/profile/Anthony-Downs-2/publication/6589844_Development_of_the_Chemistry_of_Indium_in_Formal_Oxidation_States_Lower_than_3/links/5a82db2a0f7e9bda869fb52c/Development-of-the-Chemistry-of-Indium-in-Formal-Oxidation-States-Lower-than-3.pdf?origin=publication_detail], p. 6.</ref> +1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +2<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> 
| Sn= −3,<ref>Sn(−3) has been observed in [Sn<sub>2</sub>]<sup>6−</sup>, e.g. in (Ba<sub>2</sub>)<sup>4+</sup>(Mg<sub>4</sub>)<sup>8+</sup>Sn<sup>4−</sup>(Sn<sub>2</sub>)<sup>6−</sup>Sn<sup>2−</sup> (with square (Sn<sup>2−</sup>)<sub>n</sub> sheets), see {{cite journal |last1=Papoian |first1=Garegin A. |last2=Hoffmann |first2=Roald |year=2000 |title=Hypervalent Bonding in One, Two, and Three Dimensions: Extending the Zintl–Klemm Concept to Nonclassical Electron-Rich Networks |journal=Angew. Chem. Int. Ed. |volume=2000 |issue= 39|pages=2408–2448 |url=https://www.researchgate.net/publication/12379848 |access-date=2015-02-23 |doi=10.1002/1521-3773(20000717)39:14<2408::aid-anie2408>3.0.co;2-u|pmid=10941096 }}</ref> −2,<ref>Sn(−2) has been observed in SrSn; see {{cite book|publisher=Walter de Gruyter|year=2008|edition=102| page=1007|isbn=9783110206845|title=Lehrbuch der Anorganischen Chemie|first=Arnold F.|last=Holleman |author2=Wiberg, Egon |author3=Wiberg, Nils|language=de}}</ref> −1,<ref>Sn(−1) has been observed in CsSn; see {{cite book|publisher=Walter de Gruyter|year=2008|edition=102| page=1007|isbn=9783110206845|title=Lehrbuch der Anorganischen Chemie|first=Arnold F.|last=Holleman |author2=Wiberg, Egon |author3=Wiberg, Nils|language=de}}</ref> 0,<ref name=ZeroValentTin3>{{cite web |title=New Type of Zero-Valent Tin Compound |url= https://www.chemistryviews.org/details/news/9745121/New_Type_of_Zero-Valent_Tin_Compound.html |publisher=[[Chemistry Europe]] |date=27 August 2016}}</ref> +1,<ref>{{cite web|title=HSn|url=http://webbook.nist.gov/cgi/cbook.cgi?ID=C13940255&Units=SI|work=NIST Chemistry WebBook|publisher=National Institute of Standards and Technology|access-date=23 January 2013}}</ref> +3<ref>{{cite web|title=SnH3|url=http://webbook.nist.gov/cgi/cbook.cgi?ID=B1001467&Units=SI|work=NIST Chemistry WebBook|publisher=National Institure of Standards and Technology|access-date=23 January 2013}}</ref>  
| Sb= −2,<ref name="sbanion">Sb(−2) and Sb(−1) has been observed in [Sb<sub>2</sub>]<sup>4−</sup> and <sup>1</sup><sub>∞</sub>[Sb<sub>n</sub>]<sup>n−</sup>, respectively; see {{cite journal |last1=Boss |first1=Michael |last2=Petri |first2=Denis |last3=Pickhard |first3=Frank |last4=Zönnchen |first4=Peter |last5=Röhr |first5=Caroline |year=2005 |title=Neue Barium-Antimonid-Oxide mit den Zintl-Ionen [Sb]<sup>3−</sup>, [Sb<sub>2</sub>]<sup>4−</sup> und <sup>1</sup><sub>∞</sub>[Sb<sub>n</sub>]<sup>n−</sup> / New Barium Antimonide Oxides containing Zintl Ions [Sb]<sup>3−</sup>, [Sb<sub>2</sub>]<sup>4−</sup> and <sup>1</sup><sub>∞</sub>[Sb<sub>n</sub>]<sup>n−</sup> |journal=Zeitschrift für Anorganische und Allgemeine Chemie |volume=631 |issue= 6–7|pages=1181–1190 |language=de |doi= 10.1002/zaac.200400546}}</ref> −1,<ref name="sbanion">Sb(−2) and Sb(−1) has been observed in [Sb<sub>2</sub>]<sup>4−</sup> and <sup>1</sup><sub>∞</sub>[Sb<sub>n</sub>]<sup>n−</sup>, respectively; see {{cite journal |last1=Boss |first1=Michael |last2=Petri |first2=Denis |last3=Pickhard |first3=Frank |last4=Zönnchen |first4=Peter |last5=Röhr |first5=Caroline |year=2005 |title=Neue Barium-Antimonid-Oxide mit den Zintl-Ionen [Sb]<sup>3−</sup>, [Sb<sub>2</sub>]<sup>4−</sup> und <sup>1</sup><sub>∞</sub>[Sb<sub>n</sub>]<sup>n−</sup> / New Barium Antimonide Oxides containing Zintl Ions [Sb]<sup>3−</sup>, [Sb<sub>2</sub>]<sup>4−</sup> and <sup>1</sup><sub>∞</sub>[Sb<sub>n</sub>]<sup>n−</sup> |journal=Zeitschrift für Anorganische und Allgemeine Chemie |volume=631 |issue= 6–7|pages=1181–1190 |language=de |doi= 10.1002/zaac.200400546}}</ref> 0,<ref>{{cite news|url=https://pdfs.semanticscholar.org/8817/39f9dfc007d7f77dd7baa63fe12e6079f8ef.pdf|author=Anastas Sidiropoulos|title=Studies of N-heterocyclic Carbene (NHC) Complexes of the Main Group Elements|year=2019 |page=39|doi=10.4225/03/5B0F4BDF98F60|s2cid=132399530}}
</ref> +1,<ref>Sb(I) have been observed in [[organoantimony compounds]]; see {{cite journal |last1=Šimon |first1=Petr |last2=de Proft |first2=Frank |last3=Jambor |first3=Roman |last4=Růžička |first4=Aleš |last5=Dostál |first5=Libor |year=2010 |title=Monomeric Organoantimony(I) and Organobismuth(I) Compounds Stabilized by an NCN Chelating Ligand: Syntheses and Structures |journal=Angewandte Chemie International Edition |volume=49 |issue=32 |pages=5468–5471 |doi= 10.1002/anie.201002209|pmid=20602393}}</ref> +2,<sup>?</sup> +4<ref>Sb(IV) has been observed in {{chem2|[SbCl6](2-)}}, see {{cite journal|doi=10.1246/bcsj.73.1599|title=Production of Sb(IV) Chloro Complex by Flash Photolysis of the Corresponding Sb(III) and Sb(V) Complexes in CH3CN and CHCl3|year=2000|author1=Nobuyoshi Shinohara|author2=Masaaki Ohsima|journal=Bulletin of the Chemical Society of Japan|volume=73|issue=7|pages=1599–1604}}</ref>  
| Te= −1,<sup>?</sup> 0,<sup>?</sup> +1,<sup>?</sup> +3,<sup>?</sup> +5<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref>
| I= +2,<ref>I(II) is known to exist in monoxide (IO); see {{cite journal|last1=Nikitin|first1=I V|title=Halogen monoxides|journal=Russian Chemical Reviews|date=31 August 2008|volume=77|issue=8|pages=739–749|doi=10.1070/RC2008v077n08ABEH003788|bibcode=2008RuCRv..77..739N|s2cid=250898175 }}</ref> +4,<sup>?</sup> +6<sup>?</sup>  
| Xe= 0,<ref>Xe(0) has been observed in [[tetraxenonogold(II)]] (AuXe<sub>4</sub><sup>2+</sup>).</ref> +8<ref name="Harding-2002">{{cite book|author=Harding, Charlie|author2=Johnson, David Arthur|author3= Janes, Rob |title = Elements of the ''p'' block |pages=93–94|publisher=Royal Society of Chemistry |location=Great Britain|date=2002 |isbn=0-85404-690-9 |url= https://books.google.com/books?id=W0HW8wgmQQsC&pg=PA93}}</ref> 
<!--- Period 6 --->
| Cs=−1<ref name="caeside2">{{cite journal|journal = [[Angewandte Chemie|Angewandte Chemie International Edition]]|year = 1979|first = J. L.|last = Dye|title = Compounds of Alkali Metal Anions|volume = 18|issue = 8|pages = 587–598|doi = 10.1002/anie.197905871}}</ref> 
| Ba=+1<ref>{{cite journal | doi=10.1021/acs.chemmater.8b03421 | title=A New and Facile Route Using Electride Solutions to Intercalate Alkaline Earth Ions into Graphite | year=2018 | last1=Xu | first1=Wei | last2=Lerner | first2=Michael M. | journal=Chemistry of Materials | volume=30 | issue=19 | pages=6930–6935 | s2cid=105295721 }}</ref>
| La= 0,<ref name="Cloke1993">Yttrium and all lanthanides except Ce and Pm have been observed in the oxidation state 0 in bis(1,3,5-tri-t-butylbenzene) complexes, see {{cite journal |journal=Chem. Soc. Rev. |date=1993 |volume=22 |pages=17–24 |first=F. Geoffrey N. |last=Cloke |title=Zero Oxidation State Compounds of Scandium, Yttrium, and the Lanthanides |doi=10.1039/CS9932200017}} and {{cite journal|last1=Arnold|first1=Polly L.|last2=Petrukhina|first2=Marina A.|last3=Bochenkov|first3=Vladimir E.|last4=Shabatina|first4=Tatyana I.|last5=Zagorskii|first5=Vyacheslav V.|last6=Cloke|first9=F. Geoffrey N.|date=2003-12-15|title=Arene complexation of Sm, Eu, Tm and Yb atoms: a variable temperature spectroscopic investigation|journal=Journal of Organometallic Chemistry|volume=688|issue=1–2|pages=49–55|doi=10.1016/j.jorganchem.2003.08.028}}</ref> +1,<ref name=LnI>La(I), Pr(I), Tb(I), Tm(I), and Yb(I) have been observed in MB<sub>8</sub><sup>−</sup> clusters; see {{cite journal|title=Monovalent lanthanide(I) in borozene complexes |journal=Nature Communications |volume=12 |page=6467 |year=2021 |last1=Li |first1=Wan-Lu |doi=10.1038/s41467-021-26785-9 |last2=Chen |first2=Teng-Teng |last3=Chen |first3=Wei-Jia |last4=Li |first4=Jun |last5=Wang |first5=Lai-Sheng|issue=1 |pmid=34753931 |pmc=8578558 }}</ref> +2<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> 
| Ce= +2<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref>
| Pr= 0,<ref name="Cloke1993">Yttrium and all lanthanides except Ce and Pm have been observed in the oxidation state 0 in bis(1,3,5-tri-t-butylbenzene) complexes, see {{cite journal |journal=Chem. Soc. Rev. |date=1993 |volume=22 |pages=17–24 |first=F. Geoffrey N. |last=Cloke |title=Zero Oxidation State Compounds of Scandium, Yttrium, and the Lanthanides |doi=10.1039/CS9932200017}} and {{cite journal|last1=Arnold|first1=Polly L.|last2=Petrukhina|first2=Marina A.|last3=Bochenkov|first3=Vladimir E.|last4=Shabatina|first4=Tatyana I.|last5=Zagorskii|first5=Vyacheslav V.|last6=Cloke|first9=F. Geoffrey N.|date=2003-12-15|title=Arene complexation of Sm, Eu, Tm and Yb atoms: a variable temperature spectroscopic investigation|journal=Journal of Organometallic Chemistry|volume=688|issue=1–2|pages=49–55|doi=10.1016/j.jorganchem.2003.08.028}}</ref> +1,<ref>{{cite journal|title=Lanthanides with Unusually Low Oxidation States in the PrB<sub>3</sub><sup>–</sup> and PrB<sub>4</sub><sup>–</sup> Boride Clusters|journal=Inorganic Chemistry|volume=58|issue=1|pages=411–418|last1=Chen|first1=Xin|display-authors=etal|date=2019-12-13|doi=10.1021/acs.inorgchem.8b02572|pmid=30543295|s2cid=56148031 }}</ref> +2,<ref name="Lanthanides">All the [[lanthanide]]s, except Pm, in the +2 oxidation state have been observed in organometallic molecular complexes, see [http://cen.acs.org/articles/91/i24/Lanthanides-Topple-Assumptions.html Lanthanides Topple Assumptions] and {{cite journal|doi=10.1002/anie.201311325|title=All the Lanthanides Do It and Even Uranium Does Oxidation State +2|year=2014|last1=Meyer|first1=G.|journal=Angewandte Chemie International Edition|volume=53|issue=14|pages=3550–51|pmid=24616202}}. Additionally, all the [[lanthanide]]s (La–Lu) form dihydrides (LnH<sub>2</sub>), dicarbides (LnC<sub>2</sub>), monosulfides (LnS), monoselenides (LnSe), and monotellurides (LnTe), but for most elements these compounds have Ln<sup>3+</sup> ions with electrons delocalized into conduction bands, e. g. Ln<sup>3+</sup>(H<sup>−</sup>)<sub>2</sub>(e<sup>−</sup>).</ref> +4,<sup>?</sup> +5 
| Nd= 0,<ref name="Cloke1993">Yttrium and all lanthanides except Ce and Pm have been observed in the oxidation state 0 in bis(1,3,5-tri-t-butylbenzene) complexes, see {{cite journal |journal=Chem. Soc. Rev. |date=1993 |volume=22 |pages=17–24 |first=F. Geoffrey N. |last=Cloke |title=Zero Oxidation State Compounds of Scandium, Yttrium, and the Lanthanides |doi=10.1039/CS9932200017}} and {{cite journal|last1=Arnold|first1=Polly L.|last2=Petrukhina|first2=Marina A.|last3=Bochenkov|first3=Vladimir E.|last4=Shabatina|first4=Tatyana I.|last5=Zagorskii|first5=Vyacheslav V.|last6=Cloke|first9=F. Geoffrey N.|date=2003-12-15|title=Arene complexation of Sm, Eu, Tm and Yb atoms: a variable temperature spectroscopic investigation|journal=Journal of Organometallic Chemistry|volume=688|issue=1–2|pages=49–55|doi=10.1016/j.jorganchem.2003.08.028}}</ref> +2,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +4
| Pm= +2<sup>?</sup>  
| Sm= 0,<ref name="Cloke1993">Yttrium and all lanthanides except Ce and Pm have been observed in the oxidation state 0 in bis(1,3,5-tri-t-butylbenzene) complexes, see {{cite journal |journal=Chem. Soc. Rev. |date=1993 |volume=22 |pages=17–24 |first=F. Geoffrey N. |last=Cloke |title=Zero Oxidation State Compounds of Scandium, Yttrium, and the Lanthanides |doi=10.1039/CS9932200017}} and {{cite journal|last1=Arnold|first1=Polly L.|last2=Petrukhina|first2=Marina A.|last3=Bochenkov|first3=Vladimir E.|last4=Shabatina|first4=Tatyana I.|last5=Zagorskii|first5=Vyacheslav V.|last6=Cloke|first9=F. Geoffrey N.|date=2003-12-15|title=Arene complexation of Sm, Eu, Tm and Yb atoms: a variable temperature spectroscopic investigation|journal=Journal of Organometallic Chemistry|volume=688|issue=1–2|pages=49–55|doi=10.1016/j.jorganchem.2003.08.028}}</ref> +1,<ref>SmB<sub>6</sub><sup>−</sup> cluster anion has been reported and contains Sm in rare oxidation state of +1; see {{cite journal| title=SmB<sub>6</sub><sup>–</sup> Cluster Anion: Covalency Involving f Orbitals 
|first1=J. Robinson |last1=Paul |first2=Zhang |last2=Xinxing |first3=McQueen |last3=Tyrel |first4=H. Bowen |last4=Kit |first5=N. Alexandrova |last5=Anastassia |journal=J. Phys. Chem. A 2017,<sup>?</sup> 121,<sup>?</sup> 8,<sup>?</sup> 1849–1854 |year = 2017|volume = 121|issue = 8|pages = 1849–1854|doi=10.1021/acs.jpca.7b00247 |pmid=28182423 |s2cid=3723987 |url=https://pubs.acs.org/doi/abs/10.1021/acs.jpca.7b00247#}}.</ref> +2<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> 
| Eu= 0<ref name="Cloke1993">Yttrium and all lanthanides except Ce and Pm have been observed in the oxidation state 0 in bis(1,3,5-tri-t-butylbenzene) complexes, see {{cite journal |journal=Chem. Soc. Rev. |date=1993 |volume=22 |pages=17–24 |first=F. Geoffrey N. |last=Cloke |title=Zero Oxidation State Compounds of Scandium, Yttrium, and the Lanthanides |doi=10.1039/CS9932200017}} and {{cite journal|last1=Arnold|first1=Polly L.|last2=Petrukhina|first2=Marina A.|last3=Bochenkov|first3=Vladimir E.|last4=Shabatina|first4=Tatyana I.|last5=Zagorskii|first5=Vyacheslav V.|last6=Cloke|first9=F. Geoffrey N.|date=2003-12-15|title=Arene complexation of Sm, Eu, Tm and Yb atoms: a variable temperature spectroscopic investigation|journal=Journal of Organometallic Chemistry|volume=688|issue=1–2|pages=49–55|doi=10.1016/j.jorganchem.2003.08.028}}</ref>  
| Gd= 0,<ref name="Cloke1993">Yttrium and all lanthanides except Ce and Pm have been observed in the oxidation state 0 in bis(1,3,5-tri-t-butylbenzene) complexes, see {{cite journal |journal=Chem. Soc. Rev. |date=1993 |volume=22 |pages=17–24 |first=F. Geoffrey N. |last=Cloke |title=Zero Oxidation State Compounds of Scandium, Yttrium, and the Lanthanides |doi=10.1039/CS9932200017}} and {{cite journal|last1=Arnold|first1=Polly L.|last2=Petrukhina|first2=Marina A.|last3=Bochenkov|first3=Vladimir E.|last4=Shabatina|first4=Tatyana I.|last5=Zagorskii|first5=Vyacheslav V.|last6=Cloke|first9=F. Geoffrey N.|date=2003-12-15|title=Arene complexation of Sm, Eu, Tm and Yb atoms: a variable temperature spectroscopic investigation|journal=Journal of Organometallic Chemistry|volume=688|issue=1–2|pages=49–55|doi=10.1016/j.jorganchem.2003.08.028}}</ref> +1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +2<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref>  
| Tb= 0,<ref name="Cloke1993">Yttrium and all lanthanides except Ce and Pm have been observed in the oxidation state 0 in bis(1,3,5-tri-t-butylbenzene) complexes, see {{cite journal |journal=Chem. Soc. Rev. |date=1993 |volume=22 |pages=17–24 |first=F. Geoffrey N. |last=Cloke |title=Zero Oxidation State Compounds of Scandium, Yttrium, and the Lanthanides |doi=10.1039/CS9932200017}} and {{cite journal|last1=Arnold|first1=Polly L.|last2=Petrukhina|first2=Marina A.|last3=Bochenkov|first3=Vladimir E.|last4=Shabatina|first4=Tatyana I.|last5=Zagorskii|first5=Vyacheslav V.|last6=Cloke|first9=F. Geoffrey N.|date=2003-12-15|title=Arene complexation of Sm, Eu, Tm and Yb atoms: a variable temperature spectroscopic investigation|journal=Journal of Organometallic Chemistry|volume=688|issue=1–2|pages=49–55|doi=10.1016/j.jorganchem.2003.08.028}}</ref> +1,<ref name=LnI>La(I), Pr(I), Tb(I), Tm(I), and Yb(I) have been observed in MB<sub>8</sub><sup>−</sup> clusters; see {{cite journal|title=Monovalent lanthanide(I) in borozene complexes |journal=Nature Communications |volume=12 |page=6467 |year=2021 |last1=Li |first1=Wan-Lu |doi=10.1038/s41467-021-26785-9 |last2=Chen |first2=Teng-Teng |last3=Chen |first3=Wei-Jia |last4=Li |first4=Jun |last5=Wang |first5=Lai-Sheng|issue=1 |pmid=34753931 |pmc=8578558 }}</ref> +2,<ref name="Lanthanides">All the [[lanthanide]]s, except Pm, in the +2 oxidation state have been observed in organometallic molecular complexes, see [http://cen.acs.org/articles/91/i24/Lanthanides-Topple-Assumptions.html Lanthanides Topple Assumptions] and {{cite journal|doi=10.1002/anie.201311325|title=All the Lanthanides Do It and Even Uranium Does Oxidation State +2|year=2014|last1=Meyer|first1=G.|journal=Angewandte Chemie International Edition|volume=53|issue=14|pages=3550–51|pmid=24616202}}. Additionally, all the [[lanthanide]]s (La–Lu) form dihydrides (LnH<sub>2</sub>), dicarbides (LnC<sub>2</sub>), monosulfides (LnS), monoselenides (LnSe), and monotellurides (LnTe), but for most elements these compounds have Ln<sup>3+</sup> ions with electrons delocalized into conduction bands, e. g. Ln<sup>3+</sup>(H<sup>−</sup>)<sub>2</sub>(e<sup>−</sup>).</ref> +4<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> 
| Dy= 0,<ref name="Cloke1993">Yttrium and all lanthanides except Ce and Pm have been observed in the oxidation state 0 in bis(1,3,5-tri-t-butylbenzene) complexes, see {{cite journal |journal=Chem. Soc. Rev. |date=1993 |volume=22 |pages=17–24 |first=F. Geoffrey N. |last=Cloke |title=Zero Oxidation State Compounds of Scandium, Yttrium, and the Lanthanides |doi=10.1039/CS9932200017}} and {{cite journal|last1=Arnold|first1=Polly L.|last2=Petrukhina|first2=Marina A.|last3=Bochenkov|first3=Vladimir E.|last4=Shabatina|first4=Tatyana I.|last5=Zagorskii|first5=Vyacheslav V.|last6=Cloke|first9=F. Geoffrey N.|date=2003-12-15|title=Arene complexation of Sm, Eu, Tm and Yb atoms: a variable temperature spectroscopic investigation|journal=Journal of Organometallic Chemistry|volume=688|issue=1–2|pages=49–55|doi=10.1016/j.jorganchem.2003.08.028}}</ref> +2,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +4
| Ho= 0,<ref name="Cloke1993">Yttrium and all lanthanides except Ce and Pm have been observed in the oxidation state 0 in bis(1,3,5-tri-t-butylbenzene) complexes, see {{cite journal |journal=Chem. Soc. Rev. |date=1993 |volume=22 |pages=17–24 |first=F. Geoffrey N. |last=Cloke |title=Zero Oxidation State Compounds of Scandium, Yttrium, and the Lanthanides |doi=10.1039/CS9932200017}} and {{cite journal|last1=Arnold|first1=Polly L.|last2=Petrukhina|first2=Marina A.|last3=Bochenkov|first3=Vladimir E.|last4=Shabatina|first4=Tatyana I.|last5=Zagorskii|first5=Vyacheslav V.|last6=Cloke|first9=F. Geoffrey N.|date=2003-12-15|title=Arene complexation of Sm, Eu, Tm and Yb atoms: a variable temperature spectroscopic investigation|journal=Journal of Organometallic Chemistry|volume=688|issue=1–2|pages=49–55|doi=10.1016/j.jorganchem.2003.08.028}}</ref> +2<ref name="Lanthanides">All the [[lanthanide]]s, except Pm, in the +2 oxidation state have been observed in organometallic molecular complexes, see [http://cen.acs.org/articles/91/i24/Lanthanides-Topple-Assumptions.html Lanthanides Topple Assumptions] and {{cite journal|doi=10.1002/anie.201311325|title=All the Lanthanides Do It and Even Uranium Does Oxidation State +2|year=2014|last1=Meyer|first1=G.|journal=Angewandte Chemie International Edition|volume=53|issue=14|pages=3550–51|pmid=24616202}}. Additionally, all the [[lanthanide]]s (La–Lu) form dihydrides (LnH<sub>2</sub>), dicarbides (LnC<sub>2</sub>), monosulfides (LnS), monoselenides (LnSe), and monotellurides (LnTe), but for most elements these compounds have Ln<sup>3+</sup> ions with electrons delocalized into conduction bands, e. g. Ln<sup>3+</sup>(H<sup>−</sup>)<sub>2</sub>(e<sup>−</sup>).</ref>  
| Er= 0,<ref name="Cloke1993">Yttrium and all lanthanides except Ce and Pm have been observed in the oxidation state 0 in bis(1,3,5-tri-t-butylbenzene) complexes, see {{cite journal |journal=Chem. Soc. Rev. |date=1993 |volume=22 |pages=17–24 |first=F. Geoffrey N. |last=Cloke |title=Zero Oxidation State Compounds of Scandium, Yttrium, and the Lanthanides |doi=10.1039/CS9932200017}} and {{cite journal|last1=Arnold|first1=Polly L.|last2=Petrukhina|first2=Marina A.|last3=Bochenkov|first3=Vladimir E.|last4=Shabatina|first4=Tatyana I.|last5=Zagorskii|first5=Vyacheslav V.|last6=Cloke|first9=F. Geoffrey N.|date=2003-12-15|title=Arene complexation of Sm, Eu, Tm and Yb atoms: a variable temperature spectroscopic investigation|journal=Journal of Organometallic Chemistry|volume=688|issue=1–2|pages=49–55|doi=10.1016/j.jorganchem.2003.08.028}}</ref> +2<ref name="Lanthanides">All the [[lanthanide]]s, except Pm, in the +2 oxidation state have been observed in organometallic molecular complexes, see [http://cen.acs.org/articles/91/i24/Lanthanides-Topple-Assumptions.html Lanthanides Topple Assumptions] and {{cite journal|doi=10.1002/anie.201311325|title=All the Lanthanides Do It and Even Uranium Does Oxidation State +2|year=2014|last1=Meyer|first1=G.|journal=Angewandte Chemie International Edition|volume=53|issue=14|pages=3550–51|pmid=24616202}}. Additionally, all the [[lanthanide]]s (La–Lu) form dihydrides (LnH<sub>2</sub>), dicarbides (LnC<sub>2</sub>), monosulfides (LnS), monoselenides (LnSe), and monotellurides (LnTe), but for most elements these compounds have Ln<sup>3+</sup> ions with electrons delocalized into conduction bands, e. g. Ln<sup>3+</sup>(H<sup>−</sup>)<sub>2</sub>(e<sup>−</sup>).</ref>  
| Tm= 0,<ref name="Cloke1993">Yttrium and all lanthanides except Ce and Pm have been observed in the oxidation state 0 in bis(1,3,5-tri-t-butylbenzene) complexes, see {{cite journal |journal=Chem. Soc. Rev. |date=1993 |volume=22 |pages=17–24 |first=F. Geoffrey N. |last=Cloke |title=Zero Oxidation State Compounds of Scandium, Yttrium, and the Lanthanides |doi=10.1039/CS9932200017}} and {{cite journal|last1=Arnold|first1=Polly L.|last2=Petrukhina|first2=Marina A.|last3=Bochenkov|first3=Vladimir E.|last4=Shabatina|first4=Tatyana I.|last5=Zagorskii|first5=Vyacheslav V.|last6=Cloke|first9=F. Geoffrey N.|date=2003-12-15|title=Arene complexation of Sm, Eu, Tm and Yb atoms: a variable temperature spectroscopic investigation|journal=Journal of Organometallic Chemistry|volume=688|issue=1–2|pages=49–55|doi=10.1016/j.jorganchem.2003.08.028}}</ref> +1,<ref name=LnI>La(I), Pr(I), Tb(I), Tm(I), and Yb(I) have been observed in MB<sub>8</sub><sup>−</sup> clusters; see {{cite journal|title=Monovalent lanthanide(I) in borozene complexes |journal=Nature Communications |volume=12 |page=6467 |year=2021 |last1=Li |first1=Wan-Lu |doi=10.1038/s41467-021-26785-9 |last2=Chen |first2=Teng-Teng |last3=Chen |first3=Wei-Jia |last4=Li |first4=Jun |last5=Wang |first5=Lai-Sheng|issue=1 |pmid=34753931 |pmc=8578558 }}</ref> +2<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref>
| Yb= 0,<ref name="Cloke1993">Yttrium and all lanthanides except Ce and Pm have been observed in the oxidation state 0 in bis(1,3,5-tri-t-butylbenzene) complexes, see {{cite journal |journal=Chem. Soc. Rev. |date=1993 |volume=22 |pages=17–24 |first=F. Geoffrey N. |last=Cloke |title=Zero Oxidation State Compounds of Scandium, Yttrium, and the Lanthanides |doi=10.1039/CS9932200017}} and {{cite journal|last1=Arnold|first1=Polly L.|last2=Petrukhina|first2=Marina A.|last3=Bochenkov|first3=Vladimir E.|last4=Shabatina|first4=Tatyana I.|last5=Zagorskii|first5=Vyacheslav V.|last6=Cloke|first9=F. Geoffrey N.|date=2003-12-15|title=Arene complexation of Sm, Eu, Tm and Yb atoms: a variable temperature spectroscopic investigation|journal=Journal of Organometallic Chemistry|volume=688|issue=1–2|pages=49–55|doi=10.1016/j.jorganchem.2003.08.028}}</ref> +1,<ref name=LnI>La(I), Pr(I), Tb(I), Tm(I), and Yb(I) have been observed in MB<sub>8</sub><sup>−</sup> clusters; see {{cite journal|title=Monovalent lanthanide(I) in borozene complexes |journal=Nature Communications |volume=12 |page=6467 |year=2021 |last1=Li |first1=Wan-Lu |doi=10.1038/s41467-021-26785-9 |last2=Chen |first2=Teng-Teng |last3=Chen |first3=Wei-Jia |last4=Li |first4=Jun |last5=Wang |first5=Lai-Sheng|issue=1 |pmid=34753931 |pmc=8578558 }}</ref> +2<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> 
| Lu= 0,<ref name="Cloke1993">Yttrium and all lanthanides except Ce and Pm have been observed in the oxidation state 0 in bis(1,3,5-tri-t-butylbenzene) complexes, see {{cite journal |journal=Chem. Soc. Rev. |date=1993 |volume=22 |pages=17–24 |first=F. Geoffrey N. |last=Cloke |title=Zero Oxidation State Compounds of Scandium, Yttrium, and the Lanthanides |doi=10.1039/CS9932200017}} and {{cite journal|last1=Arnold|first1=Polly L.|last2=Petrukhina|first2=Marina A.|last3=Bochenkov|first3=Vladimir E.|last4=Shabatina|first4=Tatyana I.|last5=Zagorskii|first5=Vyacheslav V.|last6=Cloke|first9=F. Geoffrey N.|date=2003-12-15|title=Arene complexation of Sm, Eu, Tm and Yb atoms: a variable temperature spectroscopic investigation|journal=Journal of Organometallic Chemistry|volume=688|issue=1–2|pages=49–55|doi=10.1016/j.jorganchem.2003.08.028}}</ref> +2<ref name="Lanthanides">All the [[lanthanide]]s, except Pm, in the +2 oxidation state have been observed in organometallic molecular complexes, see [http://cen.acs.org/articles/91/i24/Lanthanides-Topple-Assumptions.html Lanthanides Topple Assumptions] and {{cite journal|doi=10.1002/anie.201311325|title=All the Lanthanides Do It and Even Uranium Does Oxidation State +2|year=2014|last1=Meyer|first1=G.|journal=Angewandte Chemie International Edition|volume=53|issue=14|pages=3550–51|pmid=24616202}}. Additionally, all the [[lanthanide]]s (La–Lu) form dihydrides (LnH<sub>2</sub>), dicarbides (LnC<sub>2</sub>), monosulfides (LnS), monoselenides (LnSe), and monotellurides (LnTe), but for most elements these compounds have Ln<sup>3+</sup> ions with electrons delocalized into conduction bands, e. g. Ln<sup>3+</sup>(H<sup>−</sup>)<sub>2</sub>(e<sup>−</sup>).</ref>  
| Hf= −2,<ref>Hf(–2) occurs in {{chem2|Hf(CO)<sub>6</sub>(2-)}}; see {{cite journal |author1=John E. Ellis |title=Metal Carbonyl Anions:  from [Fe(CO)<sub>4</sub>]<sub>2</sub><sup>−</sup> to [Hf(CO)<sub>6</sub>]<sub>2</sub><sup>−</sup> and Beyond† |journal=Organometallics |date=2003 |volume=22 |issue=17 |pages=3322–3338 |doi=10.1021/om030105l |language=en}}</ref> 0,<ref>Hf(0) occur in (η<sup>6</sup>-(1,3,5-<sup>''t''</sup>Bu)<sub>3</sub>C<sub>6</sub>H<sub>3</sub>)<sub>2</sub>Hf and [(η<sup>5</sup>-C<sub>5</sub>R<sub>5</sub>Hf(CO)<sub>4</sub>]<sup>−</sup>, see {{cite book|publisher=Elsevier Ltd.|year=2007|volume=4|pages=697–739|doi=10.1016/B0-08-045047-4/00062-5|title=Comprehensive Organometallic Chemistry III. From Fundamentals to Applications|first=P. J.|last=Chirik |author2=Bradley, C. A. |chapter=4.06 - Complexes of Zirconium and Hafnium in Oxidation States 0 to ii|isbn=9780080450476}}</ref> +1,<ref>Hf(I) has been observed in hafnium monobromide (HfBr), see {{cite journal
 | title= Кристаллическое строение и термодинамические характеристики монобромидов циркония и гафния / Crystal structure and thermodynamic characteristics of monobromides of zirconium and hafnium
 | last1= Marek | first1= G.S. | last2= Troyanov | first2= S.I. | last3= Tsirel'nikov | first3= V.I. | journal= Журнал неорганической химии / Russian Journal of Inorganic Chemistry | year= 1979 | volume= 24 | issue= 4 | pages= 890–893 | language= ru | url= https://inis.iaea.org/search/search.aspx?orig_q=RN:11520917}}</ref> +2,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +3<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref>
| Ta= −3,<ref>Ta(–3) occurs in {{chem2|Ta(CO)<sub>5</sub>(3-)}}; see {{cite journal |author1=John E. Ellis |title=Metal Carbonyl Anions:  from [Fe(CO)<sub>4</sub>]<sub>2</sub><sup>−</sup> to [Hf(CO)<sub>6</sub>]<sub>2</sub><sup>−</sup> and Beyond† |journal=Organometallics |date=2003 |volume=22 |issue=17 |pages=3322–3338 |doi=10.1021/om030105l |language=en}}</ref> −1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> 0,<ref>Ta(0) is known in Ta(CNDipp)<sub>6</sub>; see {{cite journal |author1=Khetpakorn Chakarawet |author2=Zachary W. Davis-Gilbert |author3=Stephanie R. Harstad |author4=Victor G. Young Jr. |author5=Jeffrey R. Long |author6=John E. Ellis |title=Ta(CNDipp)6: An Isocyanide Analogue of Hexacarbonyltantalum(0) |journal=Angewandte Chemie International Edition |date=2017 |volume=56 |issue=35 |pages=10577-10581 |doi=10.1002/anie.201706323 |language=en}} Additionally, Ta(0) has also been previously reported in Ta(bipy)<sub>3</sub>, but this has been proven to contain Ta(V).</ref> +1,<ref>Ta(I) has been observed in CpTa(CO)<sub>4</sub>; see {{cite book|publisher=Walter de Gruyter|year=2008|edition=102| pages=1554|isbn=9783110206845|title=Lehrbuch der Anorganischen Chemie|first=Arnold F.|last=Holleman |author2=Wiberg, Egon |author3=Wiberg, Nils|language=de}}</ref> +2,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +3,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +4<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref>
| W= −4,<ref>W(−4) is known in {{chem2|W(CO)4(4-)}}; see {{cite journal |author1=John E. Ellis |title=Adventures with Substances Containing Metals in Negative Oxidation States |journal=Inorganic Chemistry |date=2006 |volume=45 |issue=8 |doi=10.1021/ic052110i |language=en}}</ref> −2,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> −1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> 0,<ref>W(0) is known in {{chem2|W(CO)6}}; see {{cite journal |author1=John E. Ellis |title=Adventures with Substances Containing Metals in Negative Oxidation States |journal=Inorganic Chemistry |date=2006 |volume=45 |issue=8 |doi=10.1021/ic052110i |language=en}}</ref> +1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +2,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +3,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +5<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref>
| Re= −3,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> −1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> 0,<ref>Re(0) is known in [[Dirhenium decacarbonyl|{{chem2|Re2(CO)10}}]]; see {{cite journal |author1=John E. Ellis |title=Adventures with Substances Containing Metals in Negative Oxidation States |journal=Inorganic Chemistry |date=2006 |volume=45 |issue=8 |doi=10.1021/ic052110i |language=en}}</ref> +1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +2,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +3,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +5,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +6,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref>
| Os= −4,<sup>?</sup> −2,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> −1,<sup>?</sup> 0,<sup>?</sup> +1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +2,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +3,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +5,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +6,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +7,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +8<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref>
| Ir= −3,<sup>?</sup> −2,<sup>?</sup> −1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> 0,<sup>?</sup> +1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +2,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +5,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +6,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +7,<sup>?</sup> +8,<sup>?</sup> +9<ref name=IrIX>{{cite journal |last1=Wang |first1=Guanjun |last2=Zhou |first2=Mingfei |last3=Goettel |first3=James T. |last4=Schrobilgen |first4=Gary G. |last5=Su |first5=Jing |last6=Li |first6=Jun |last7=Schlöder |first7=Tobias |last8=Riedel |first8=Sebastian |date=2014 |title=Identification of an iridium-containing compound with a formal oxidation state of IX |journal=Nature |volume=514 |issue=7523 |pages=475–477 |doi=10.1038/nature13795 |pmid=25341786|bibcode=2014Natur.514..475W |s2cid=4463905 }}</ref>
| Pt= −3,<sup>?</sup> −2,<sup>?</sup> −1,<sup>?</sup> 0,<sup>?</sup> +1,<sup>?</sup> +3,<sup>?</sup> +5,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +6<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref>
| Au= −3,<sup>?</sup> −2,<sup>?</sup> −1,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> 0, +1,<ref>{{cite journal |doi= 10.1002/(SICI)1521-3773(19991102)38:21<3194::AID-ANIE3194>3.0.CO;2-O |title= Gold(I) and Gold(0) Complexes of Phosphinine‐Based Macrocycles|first1=Nicolas |last1= Mézaille |first2=Narcis |last2=Avarvari |first3=Nicole |last3=Maigrot|first4=Louis |last4=Ricard|first5=François |last5=Mathey|first6=Pascal |last6=Le Floch|first7=Laurent|last7=Cataldo|first8=Théo|last8=Berclaz|first9=Michel|last9=Geoffroy|journal= Angewandte Chemie International Edition|year= 1999 |volume= 38|issue= 21|pages= 3194–3197|pmid= 10556900}}</ref> +2,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +5<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref>
| Hg= −2<ref name="Brauer-1936">{{Cite journal |last=Brauer |first=G. |last2=Haucke |first2=W. |date=1936-06-01 |title=Kristallstruktur der intermetallischen Phasen MgAu und MgHg |url=https://www.degruyter.com/document/doi/10.1515/zpch-1936-3327/html |journal=Zeitschrift für Physikalische Chemie |language=en |volume=33B |issue=1 |pages=304–310 |doi=10.1515/zpch-1936-3327 |issn=2196-7156 |quote=MgHg then lends itself to an oxidation state of +2 for Mg and -2 for Hg because it consists entirely of these polar bonds with no evidence of electron unpairing. (translated)}}</ref>
| Tl= −5,<ref>{{cite journal|doi=10.1021/ic960014z|title=Na<sub>23</sub>K<sub>9</sub>Tl<sub>15.3</sub>: An Unusual Zintl Compound Containing Apparent Tl<sub>5</sub><sup>7−</sup>, Tl<sub>4</sub><sup>8−</sup>, Tl<sub>3</sub><sup>7−</sup>, and Tl<sup>5−</sup> Anions|year=1996|last1=Dong|first1=Z.-C.|last2=Corbett|first2=J. D.|journal=Inorganic Chemistry|volume=35|issue=11|pages=3107–12|pmid=11666505 }}</ref><!-- is about a Tl 7- then? --> −2,<sup>?</sup> −1,<sup>?</sup> +2<sup>?</sup>  
| Pb= −4,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> −2,<sup>?</sup> −1,<sup>?</sup> 0,<ref>Pb(0) carbonyls have been observered in reaction between lead atoms and [[carbon monoxide]]; see {{cite journal|url=https://aip.scitation.org/doi/10.1063/1.1834915 | title= Observation of the lead carbonyls Pb<sub>n</sub>CO (n=1–4): Reactions of lead atoms and small clusters with carbon monoxide in solid argon
|first1=Jiang |last1=Ling |first2=Xu |last2=Qiang |journal=The Journal of Chemical Physics. 122 (3): 034505 |year = 2005|volume = 122|issue = 3|page = 34505|doi=10.1063/1.1834915 |pmid = 15740207|bibcode = 2005JChPh.122c4505J|issn=0021-9606}}</ref> +1,<sup>?</sup> +3<sup>?</sup>  
| Bi= −3,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> −2,<sup>?</sup> −1,<sup>?</sup> 0,<ref>Bi(0) state exists in a [[Heterocyclic compound|N-heterocyclic carbene]] complex of dibismuthene; see {{cite journal |first1=Rajesh |last1=Deka |first2=Andreas |last2=Orthaber |title=Carbene chemistry of arsenic, antimony, and bismuth: origin, evolution and future prospects |journal=Royal Society of Chemistry |issue=22 |date=May 9, 2022 |volume=51 |pages=8540–8556 |doi=10.1039/d2dt00755j |pmid=35578901|s2cid=248675805 }}</ref> +1,<sup>?</sup> +2,<sup>?</sup> +4,<sup>?</sup> +5<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> 
| Po= +5<ref name="Thayer p78">{{cite journal |last1=Thayer |first1=John S. |journal=Relativistic Methods for Chemists |title=Relativistic Effects and the Chemistry of the Heavier Main Group Elements |series=Challenges and Advances in Computational Chemistry and Physics |year=2010 |volume=10 |page=78 |doi=10.1007/978-1-4020-9975-5_2|isbn=978-1-4020-9974-8 }}</ref> +6,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref>
| At= +3,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +5,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +7<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref>
| Rn= +2,<sup>?</sup> +6
<!--- Period 7 --->
| Fr=
| Ra=
| Ac=
| Th=−1,<ref name="Th(-1), U(-1)">Th(-I) and U(-I) have been detected in the gas phase as octacarbonyl anions; see {{cite journal| title=Octacarbonyl Ion Complexes of Actinides [An(CO)<sub>8</sub>]<sup>+/−</sup> (An=Th, U) and the Role of f Orbitals in Metal–Ligand Bonding 
|first1=Chi |last1=Chaoxian |first2=Pan |last2=Sudip |first3=Jin |last3=Jiaye |first4=Meng |last4=Luyan |first5=Luo |last5=Mingbiao |first6=Zhao |last6=Lili |first7=Zhou |last7=Mingfei |first8=Frenking |last8=Gernot |journal=Chemistry (Weinheim an der Bergstrasse, Germany). 25 (50): 11772–11784 |year = 2019|volume = 25|issue = 50|pages = 11772–11784|doi=10.1002/chem.201902625 |issn=0947-6539 |pmc=6772027
|pmid=31276242}}</ref> +1,<sup>?</sup> +2,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +3<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref>
| Pa=+2,<sup>?</sup> +3,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +4<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> 
| U=−1,<ref name="Th(-1), U(-1)">Th(-I) and U(-I) have been detected in the gas phase as octacarbonyl anions; see {{cite journal| title=Octacarbonyl Ion Complexes of Actinides [An(CO)<sub>8</sub>]<sup>+/−</sup> (An=Th, U) and the Role of f Orbitals in Metal–Ligand Bonding 
|first1=Chi |last1=Chaoxian |first2=Pan |last2=Sudip |first3=Jin |last3=Jiaye |first4=Meng |last4=Luyan |first5=Luo |last5=Mingbiao |first6=Zhao |last6=Lili |first7=Zhou |last7=Mingfei |first8=Frenking |last8=Gernot |journal=Chemistry (Weinheim an der Bergstrasse, Germany). 25 (50): 11772–11784 |year = 2019|volume = 25|issue = 50|pages = 11772–11784|doi=10.1002/chem.201902625 |issn=0947-6539 |pmc=6772027
|pmid=31276242}}</ref> +1,<sup>?</sup> +2,<sup>?</sup> +3,<ref>{{cite book|title=The Chemistry of the Actinide and Transactinide Elements|edition=3rd|editor1=Morss, L.R. |editor2=Edelstein, N.M. |editor3=Fuger, J. |place=Netherlands|publisher=Springer|year=2006|isbn=978-9048131464}}</ref> +4,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +5<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> 
| Np= +2,<sup>?</sup> +3,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +4,<ref name="Dutkiewicz2017">Np(II), (III) and (IV) have been observed, see {{cite journal|doi=10.1039/C7SC00034K|pmid=28553487|pmc=5431675|year=2017|title=Reduction chemistry of neptunium cyclopentadienide complexes: from structure to understanding|first1=Michał S.|last1=Dutkiewicz|first2=Christos|last2=Apostolidis|first3=Olaf|last3=Walter|first4=Polly L|last4=Arnold|volume=8|issue=4|journal=Chem. Sci.|pages=2553–2561}}</ref> +6,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +7<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref>
| Pu= +2,<sup>?</sup> +3,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref>, +5,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +6,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +7,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +8
| Am= +2,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +4,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +5,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +6,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +7
| Cm= +4,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +5,<ref name="Kovács2018">{{cite journal |last1=Kovács |first1=Attila |last2=Dau |first2=Phuong D. |last3=Marçalo |first3=Joaquim |last4=Gibson |first4=John K. |date=2018 |title=Pentavalent Curium, Berkelium, and Californium in Nitrate Complexes: Extending Actinide Chemistry and Oxidation States |journal=Inorg. Chem. |volume=57 |issue=15 |pages=9453–9467 |publisher=American Chemical Society |doi=10.1021/acs.inorgchem.8b01450 |pmid=30040397 |osti=1631597 |s2cid=51717837 }}</ref> +6<ref name="CmO3">{{cite journal |last1=Domanov |first1=V. P. |last2=Lobanov |first2=Yu. V. |date=October 2011 |title=Formation of volatile curium(VI) trioxide CmO<sub>3</sub> |journal=Radiochemistry |volume=53 |issue=5 |pages=453–6 |publisher=SP MAIK Nauka/Interperiodica |doi=10.1134/S1066362211050018|s2cid=98052484 }}</ref> 
| Bk=+2,<sup>?</sup> +4,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +5<ref name="Kovács2018">{{cite journal |last1=Kovács |first1=Attila |last2=Dau |first2=Phuong D. |last3=Marçalo |first3=Joaquim |last4=Gibson |first4=John K. |date=2018 |title=Pentavalent Curium, Berkelium, and Californium in Nitrate Complexes: Extending Actinide Chemistry and Oxidation States |journal=Inorg. Chem. |volume=57 |issue=15 |pages=9453–9467 |publisher=American Chemical Society |doi=10.1021/acs.inorgchem.8b01450 |pmid=30040397 |osti=1631597 |s2cid=51717837 }}</ref>
| Cf=+2,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +4,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +5<ref>{{Greenwood&Earnshaw2nd|page=1265}}</ref><ref name="Kovács2018">{{cite journal |last1=Kovács |first1=Attila |last2=Dau |first2=Phuong D. |last3=Marçalo |first3=Joaquim |last4=Gibson |first4=John K. |date=2018 |title=Pentavalent Curium, Berkelium, and Californium in Nitrate Complexes: Extending Actinide Chemistry and Oxidation States |journal=Inorg. Chem. |volume=57 |issue=15 |pages=9453–9467 |publisher=American Chemical Society |doi=10.1021/acs.inorgchem.8b01450 |pmid=30040397 |osti=1631597 |s2cid=51717837 }}</ref>
| Es=+2,<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref> +4
| Fm=+2<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref>
| Md=+2<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref>
| No=+2<ref name=GE28>{{Greenwood&Earnshaw2nd|page=28}}</ref>
| Lr=
<!-- default to blank -->
}}
|predicted={{#switch:{{{symbol|}}}
| Rf=(+3), (+4)<!-- source for 3,4 --><ref name=Haire>{{cite book| title=The Chemistry of the Actinide and Transactinide Elements| editor1-last=Morss| editor2-first=Norman M.| editor2-last=Edelstein| editor3-last=Fuger| editor3-first=Jean| last1=Hoffman| first1=Darleane C.| last2=Lee| first2=Diana M.| last3=Pershina| first3=Valeria| chapter=Transactinides and the future elements| publisher=[[Springer Science+Business Media]]| year=2006| isbn=978-1-4020-3555-5| location=Dordrecht, The Netherlands| edition=3rd| ref=CITEREFHaire2006}}</ref>
| Db= (+3), (+4), (+5)<!-- source for 3,4,5 --><ref name=Haire>{{cite book| title=The Chemistry of the Actinide and Transactinide Elements| editor1-last=Morss| editor2-first=Norman M.| editor2-last=Edelstein| editor3-last=Fuger| editor3-first=Jean| last1=Hoffman| first1=Darleane C.| last2=Lee| first2=Diana M.| last3=Pershina| first3=Valeria| chapter=Transactinides and the future elements| publisher=[[Springer Science+Business Media]]| year=2006| isbn=978-1-4020-3555-5| location=Dordrecht, The Netherlands| edition=3rd| ref=CITEREFHaire2006}}</ref>
| Sg= (+3), (+4), (+5), (+6)<!-- source for 3,4,5,6 --><ref name=Haire>{{cite book| title=The Chemistry of the Actinide and Transactinide Elements| editor1-last=Morss| editor2-first=Norman M.| editor2-last=Edelstein| editor3-last=Fuger| editor3-first=Jean| last1=Hoffman| first1=Darleane C.| last2=Lee| first2=Diana M.| last3=Pershina| first3=Valeria| chapter=Transactinides and the future elements| publisher=[[Springer Science+Business Media]]| year=2006| isbn=978-1-4020-3555-5| location=Dordrecht, The Netherlands| edition=3rd| ref=CITEREFHaire2006}}</ref>
| Bh= (+3), (+4), (+5), (+7)<!-- source for 3,4,5,7 --><ref name=Haire>{{cite book| title=The Chemistry of the Actinide and Transactinide Elements| editor1-last=Morss| editor2-first=Norman M.| editor2-last=Edelstein| editor3-last=Fuger| editor3-first=Jean| last1=Hoffman| first1=Darleane C.| last2=Lee| first2=Diana M.| last3=Pershina| first3=Valeria| chapter=Transactinides and the future elements| publisher=[[Springer Science+Business Media]]| year=2006| isbn=978-1-4020-3555-5| location=Dordrecht, The Netherlands| edition=3rd| ref=CITEREFHaire2006}}</ref>
| Hs= (+3), (+4), (+6), (+8)<!-- source for 3,4,6,8 --><ref name=Haire>{{cite book| title=The Chemistry of the Actinide and Transactinide Elements| editor1-last=Morss| editor2-first=Norman M.| editor2-last=Edelstein| editor3-last=Fuger| editor3-first=Jean| last1=Hoffman| first1=Darleane C.| last2=Lee| first2=Diana M.| last3=Pershina| first3=Valeria| chapter=Transactinides and the future elements| publisher=[[Springer Science+Business Media]]| year=2006| isbn=978-1-4020-3555-5| location=Dordrecht, The Netherlands| edition=3rd| ref=CITEREFHaire2006}}</ref>
| Mt= (+1), (+3), (+6)<!-- source for 1,3,6 --><ref name=Haire>{{cite book| title=The Chemistry of the Actinide and Transactinide Elements| editor1-last=Morss| editor2-first=Norman M.| editor2-last=Edelstein| editor3-last=Fuger| editor3-first=Jean| last1=Hoffman| first1=Darleane C.| last2=Lee| first2=Diana M.| last3=Pershina| first3=Valeria| chapter=Transactinides and the future elements| publisher=[[Springer Science+Business Media]]| year=2006| isbn=978-1-4020-3555-5| location=Dordrecht, The Netherlands| edition=3rd| ref=CITEREFHaire2006}}</ref>
| Ds= (+2), (+4), (+6)<!-- source for 2,4,6 --><ref name=Haire>{{cite book| title=The Chemistry of the Actinide and Transactinide Elements| editor1-last=Morss| editor2-first=Norman M.| editor2-last=Edelstein| editor3-last=Fuger| editor3-first=Jean| last1=Hoffman| first1=Darleane C.| last2=Lee| first2=Diana M.| last3=Pershina| first3=Valeria| chapter=Transactinides and the future elements| publisher=[[Springer Science+Business Media]]| year=2006| isbn=978-1-4020-3555-5| location=Dordrecht, The Netherlands| edition=3rd| ref=CITEREFHaire2006}}</ref>
| Rg= (−1), (+3), (+5)<!-- source for -1,+3,+5 --><ref name=Haire>{{cite book| title=The Chemistry of the Actinide and Transactinide Elements| editor1-last=Morss| editor2-first=Norman M.| editor2-last=Edelstein| editor3-last=Fuger| editor3-first=Jean| last1=Hoffman| first1=Darleane C.| last2=Lee| first2=Diana M.| last3=Pershina| first3=Valeria| chapter=Transactinides and the future elements| publisher=[[Springer Science+Business Media]]| year=2006| isbn=978-1-4020-3555-5| location=Dordrecht, The Netherlands| edition=3rd| ref=CITEREFHaire2006}}</ref>
| Cn= (+2), (+4)<!-- source for 2,4 --><ref name=Haire>{{cite book| title=The Chemistry of the Actinide and Transactinide Elements| editor1-last=Morss| editor2-first=Norman M.| editor2-last=Edelstein| editor3-last=Fuger| editor3-first=Jean| last1=Hoffman| first1=Darleane C.| last2=Lee| first2=Diana M.| last3=Pershina| first3=Valeria| chapter=Transactinides and the future elements| publisher=[[Springer Science+Business Media]]| year=2006| isbn=978-1-4020-3555-5| location=Dordrecht, The Netherlands| edition=3rd| ref=CITEREFHaire2006}}</ref>
| Nh=
| Fl=
| Mc=
| Lv= (−2),<ref name="Thayer p83">{{cite journal |last1=Thayer |first1=John S. |journal=Relativistic Methods for Chemists |title=Relativistic Effects and the Chemistry of the Heavier Main Group Elements |series=Challenges and Advances in Computational Chemistry and Physics |year=2010 |volume=10 |page=83 |doi=10.1007/978-1-4020-9975-5_2|isbn=978-1-4020-9974-8 }}</ref>   (+4)
| Ts= (−1), (+5)
| Og= (−1),<ref name=Haire>{{cite book| title=The Chemistry of the Actinide and Transactinide Elements| editor1-last=Morss| editor2-first=Norman M.| editor2-last=Edelstein| editor3-last=Fuger| editor3-first=Jean| last1=Hoffman| first1=Darleane C.| last2=Lee| first2=Diana M.| last3=Pershina| first3=Valeria| chapter=Transactinides and the future elements| publisher=[[Springer Science+Business Media]]| year=2006| isbn=978-1-4020-3555-5| location=Dordrecht, The Netherlands| edition=3rd| ref=CITEREFHaire2006}}</ref> (+1),<ref name=hydride>{{cite journal|journal=Journal of Chemical Physics |volume=112|issue=6|year=2000|title=Spin–orbit effects on the transactinide p-block element monohydrides MH (M=element 113–118)|first1=Young-Kyu|last1=Han|first2=Cheolbeom |last2=Bae|first3=Sang-Kil |last3=Son|first4=Yoon Sup|last4=Lee|doi=10.1063/1.480842|page=2684|bibcode=2000JChPh.112.2684H}}</ref> (+2),<ref name=Kaldor/> (+4),<ref name=Kaldor>{{cite book|title=Theoretical Chemistry and Physics of Heavy and Superheavy Elements|first1=Uzi |last1=Kaldor |first2=Stephen |last2=Wilson |page=105 |year=2003 |publisher=Springer|isbn=978-1402013713|url=https://books.google.com/books?id=0xcAM5BzS-wC&q=element+118+properties|access-date=2008-01-18}}</ref> (+6)<ref name=Haire>{{cite book| title=The Chemistry of the Actinide and Transactinide Elements| editor1-last=Morss| editor2-first=Norman M.| editor2-last=Edelstein| editor3-last=Fuger| editor3-first=Jean| last1=Hoffman| first1=Darleane C.| last2=Lee| first2=Diana M.| last3=Pershina| first3=Valeria| chapter=Transactinides and the future elements| publisher=[[Springer Science+Business Media]]| year=2006| isbn=978-1-4020-3555-5| location=Dordrecht, The Netherlands| edition=3rd| ref=CITEREFHaire2006}}</ref>
<!--- Period 8 --->
| Uue= (+1), (+3), (+5)<ref name=Haire>{{cite book| title=The Chemistry of the Actinide and Transactinide Elements| editor1-last=Morss| editor2-first=Norman M.| editor2-last=Edelstein| editor3-last=Fuger| editor3-first=Jean| last1=Hoffman| first1=Darleane C.| last2=Lee| first2=Diana M.| last3=Pershina| first3=Valeria| chapter=Transactinides and the future elements| publisher=[[Springer Science+Business Media]]| year=2006| isbn=978-1-4020-3555-5| location=Dordrecht, The Netherlands| edition=3rd| ref=CITEREFHaire2006}}</ref><ref name=Cao>{{cite journal |last1=Cao |first1=Chang-Su |last2=Hu |first2=Han-Shi |last3=Schwarz |first3=W. H. Eugen |last4=Li |first4=Jun |date=2022 |title=Periodic Law of Chemistry Overturns for Superheavy Elements |type=preprint |url=https://chemrxiv.org/engage/chemrxiv/article-details/63730be974b7b6d84cfdda35 |journal=[[ChemRxiv]] |volume= |issue= |pages= |doi=10.26434/chemrxiv-2022-l798p |access-date=16 November 2022}}</ref>
| Ubn= (+2),<ref name=Thayer>{{cite journal |last1=Thayer |first1=John S. |journal=Relativistic Methods for Chemists |title=Relativistic Effects and the Chemistry of the Heavier Main Group Elements |series=Challenges and Advances in Computational Chemistry and Physics |year=2010 |volume=10 |page=84 |doi=10.1007/978-1-4020-9975-5_2|isbn=978-1-4020-9974-8 }}</ref> (+4), (+6)<ref name=Haire>{{cite book| title=The Chemistry of the Actinide and Transactinide Elements| editor1-last=Morss| editor2-first=Norman M.| editor2-last=Edelstein| editor3-last=Fuger| editor3-first=Jean| last1=Hoffman| first1=Darleane C.| last2=Lee| first2=Diana M.| last3=Pershina| first3=Valeria| chapter=Transactinides and the future elements| publisher=[[Springer Science+Business Media]]| year=2006| isbn=978-1-4020-3555-5| location=Dordrecht, The Netherlands| edition=3rd| ref=CITEREFHaire2006}}</ref><ref name=Cao>{{cite journal |last1=Cao |first1=Chang-Su |last2=Hu |first2=Han-Shi |last3=Schwarz |first3=W. H. Eugen |last4=Li |first4=Jun |date=2022 |title=Periodic Law of Chemistry Overturns for Superheavy Elements |type=preprint |url=https://chemrxiv.org/engage/chemrxiv/article-details/63730be974b7b6d84cfdda35 |journal=[[ChemRxiv]] |volume= |issue= |pages= |doi=10.26434/chemrxiv-2022-l798p |access-date=16 November 2022}}</ref>
| Ubu= (+3)<ref name=Haire>{{cite book| title=The Chemistry of the Actinide and Transactinide Elements| editor1-last=Morss| editor2-first=Norman M.| editor2-last=Edelstein| editor3-last=Fuger| editor3-first=Jean| last1=Hoffman| first1=Darleane C.| last2=Lee| first2=Diana M.| last3=Pershina| first3=Valeria| chapter=Transactinides and the future elements| publisher=[[Springer Science+Business Media]]| year=2006| isbn=978-1-4020-3555-5| location=Dordrecht, The Netherlands| edition=3rd| ref=CITEREFHaire2006}}</ref><ref name=Amador>{{cite journal |last1=Amador |first1=Davi H. T. |last2=de Oliveira |first2=Heibbe C. B. |first3=Julio R. |last3=Sambrano |first4=Ricardo |last4=Gargano |first5=Luiz Guilherme M. |last5=de Macedo |date=12 September 2016 |title=4-Component correlated all-electron study on Eka-actinium Fluoride (E121F) including Gaunt interaction: Accurate analytical form, bonding and influence on rovibrational spectra |journal=Chemical Physics Letters |volume=662 |pages=169–175 |doi=10.1016/j.cplett.2016.09.025|bibcode=2016CPL...662..169A |hdl=11449/168956 }}</ref> 
| Ubb= (+4)<ref name="Pyykkö2011">{{Cite journal|last1=Pyykkö|first1=Pekka|author-link=Pekka Pyykkö|title=A suggested periodic table up to Z ≤ 172, based on Dirac–Fock calculations on atoms and ions|journal=Physical Chemistry Chemical Physics|volume=13|issue=1|pages=161–8|year=2011|pmid=20967377|doi=10.1039/c0cp01575j|bibcode = 2011PCCP...13..161P }}</ref>
| Ubt= 
| Ubq= (+6)<ref name="Pyykkö2011">{{Cite journal|last1=Pyykkö|first1=Pekka|author-link=Pekka Pyykkö|title=A suggested periodic table up to Z ≤ 172, based on Dirac–Fock calculations on atoms and ions|journal=Physical Chemistry Chemical Physics|volume=13|issue=1|pages=161–8|year=2011|pmid=20967377|doi=10.1039/c0cp01575j|bibcode = 2011PCCP...13..161P }}</ref>
| Ubp=(+6), (+7)<ref name="Pyykkö2011">{{Cite journal|last1=Pyykkö|first1=Pekka|author-link=Pekka Pyykkö|title=A suggested periodic table up to Z ≤ 172, based on Dirac–Fock calculations on atoms and ions|journal=Physical Chemistry Chemical Physics|volume=13|issue=1|pages=161–8|year=2011|pmid=20967377|doi=10.1039/c0cp01575j|bibcode = 2011PCCP...13..161P }}</ref><!-- for +6 and +7--> 
| Ubh=(+4), (+6), (+8)<ref name="Pyykkö2011">{{Cite journal|last1=Pyykkö|first1=Pekka|author-link=Pekka Pyykkö|title=A suggested periodic table up to Z ≤ 172, based on Dirac–Fock calculations on atoms and ions|journal=Physical Chemistry Chemical Physics|volume=13|issue=1|pages=161–8|year=2011|pmid=20967377|doi=10.1039/c0cp01575j|bibcode = 2011PCCP...13..161P }}</ref><!-- for +4 +6 +8-->
| Ubo=(){{Infobox element/symbol-to-oxidation-state/comment|comment=predicted|engvar={{{engvar|}}}}}<ref name="Pyykkö2011">{{Cite journal|last1=Pyykkö|first1=Pekka|author-link=Pekka Pyykkö|title=A suggested periodic table up to Z ≤ 172, based on Dirac–Fock calculations on atoms and ions|journal=Physical Chemistry Chemical Physics|volume=13|issue=1|pages=161–8|year=2011|pmid=20967377|doi=10.1039/c0cp01575j|bibcode = 2011PCCP...13..161P }}</ref>
| Ube=(), (){{Infobox element/symbol-to-oxidation-state/comment|comment=predicted|engvar={{{engvar|}}}}}<ref name="Pyykkö2011">{{Cite journal|last1=Pyykkö|first1=Pekka|author-link=Pekka Pyykkö|title=A suggested periodic table up to Z ≤ 172,<sup>?</sup> based on Dirac–Fock calculations on atoms and ions|journal=Physical Chemistry Chemical Physics|volume=13|issue=1|pages=161–8|year=2011|pmid=20967377|doi=10.1039/c0cp01575j|bibcode = 2011PCCP...13..161P }}</ref>
| Uts=

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