Wikipedia

Template:List of oxidation states of the elements

  Noble gas
+1 Bold values are main oxidation states
Oxidation states of the elements
Element Negative states Positive states Group Notes
−5 −4 −3 −2 −1 0 +1 +2 +3 +4 +5 +6 +7 +8 +9
Z
1 hydrogen H −1 0 +1 1 [1]
2 helium He 0 18 [2]
3 lithium Li 0 +1 1 [3][4]
4 beryllium Be 0 +1 +2 2 [5][6]
5 boron B −5 −1 0 +1 +2 +3 13 [7][8][9]
6 carbon C −4 −3 −2 −1 0 +1 +2 +3 +4 14
7 nitrogen N −3 −2 −1 0 +1 +2 +3 +4 +5 15 [10]
8 oxygen O −2 −1 0 +1 +2 16
9 fluorine F −1 0 17 [11][12]
10 neon Ne 0 18 [13]
11 sodium Na −1 0 +1 1 [3][14]
12 magnesium Mg 0 +1 +2 2 [15][16]
13 aluminium Al −2 −1 0 +1 +2 +3 13 [17][18][19][20]
14 silicon Si −4 −3 −2 −1 0 +1 +2 +3 +4 14 [21]
15 phosphorus P −3 −2 −1 0 +1 +2 +3 +4 +5 15 [22]
16 sulfur S −2 −1 0 +1 +2 +3 +4 +5 +6 16
17 chlorine Cl −1 0 +1 +2 +3 +4 +5 +6 +7 17 [23][24]
18 argon Ar 0 18 [25]
19 potassium K −1 +1 1 [3]
20 calcium Ca +1 +2 2 [26][27]
21 scandium Sc 0 +1 +2 +3 3 [28][29][30]
22 titanium Ti −2 −1 0 +1 +2 +3 +4 4 [31][32][33][34]
23 vanadium V −3 −1 0 +1 +2 +3 +4 +5 5 [32]
24 chromium Cr −4 −2 −1 0 +1 +2 +3 +4 +5 +6 6 [32]
25 manganese Mn −3 −1 0 +1 +2 +3 +4 +5 +6 +7 7 [35][36]
26 iron Fe −4 −2 −1 0 +1 +2 +3 +4 +5 +6 +7 8 [37][38][39]
27 cobalt Co −3 −1 0 +1 +2 +3 +4 +5 9 [32]
28 nickel Ni −2 −1 0 +1 +2 +3 +4 10 [40]
29 copper Cu −2 0 +1 +2 +3 +4 11 [39][41]
30 zinc Zn −2 0 +1 +2 12 [39][42][43][44]
31 gallium Ga −5 −4 −3 −2 −1 0 +1 +2 +3 13 [18][45][46][47]
32 germanium Ge −4 −3 −2 −1 0 +1 +2 +3 +4 14 [48][21]
33 arsenic As −3 −2 −1 0 +1 +2 +3 +4 +5 15 [18][49][50][51]
34 selenium Se −2 −1 0 +1 +2 +3 +4 +5 +6 16 [52][53][54][55][56]
35 bromine Br −1 0 +1 +2 +3 +4 +5 +7 17 [57][58]
36 krypton Kr 0 +1 +2 18
37 rubidium Rb −1 +1 1 [3]
38 strontium Sr +1 +2 2 [59][27]
39 yttrium Y 0 +1 +2 +3 3 [60][61][62]
40 zirconium Zr −2 0 +1 +2 +3 +4 4 [32][63][64]
41 niobium Nb −3 −1 0 +1 +2 +3 +4 +5 5 [32][65][66]
42 molybdenum Mo −4 −2 −1 0 +1 +2 +3 +4 +5 +6 6 [32]
43 technetium Tc −1 0 +1 +2 +3 +4 +5 +6 +7 7 [67]
44 ruthenium Ru −4 −2 0 +1 +2 +3 +4 +5 +6 +7 +8 8 [32][39]
45 rhodium Rh −3 −1 0 +1 +2 +3 +4 +5 +6 +7 9 [32][68][69]
46 palladium Pd 0 +1 +2 +3 +4 +5 10 [70][71][72][73]
47 silver Ag −2 −1 0 +1 +2 +3 11 [39][74][75]
48 cadmium Cd −2 +1 +2 12 [39][76]
49 indium In −5 −2 −1 0 +1 +2 +3 13 [18][77][78][79]
50 tin Sn −4 −3 −2 −1 0 +1 +2 +3 +4 14 [18][80][81][21]
51 antimony Sb −3 −2 −1 0 +1 +2 +3 +4 +5 15 [18][82][83][84][85]
52 tellurium Te −2 −1 0 +1 +2 +3 +4 +5 +6 16 [18][86][87][88][89]
53 iodine I −1 0 +1 +2 +3 +4 +5 +6 +7 17 [90][91][92][93]
54 xenon Xe 0 +2 +4 +6 +8 18 [94][95][96]
55 caesium Cs −1 +1 1 [3]
56 barium Ba +1 +2 2 [97][27]
57 lanthanum La 0 +1 +2 +3 f-block groups [60][98]
58 cerium Ce +2 +3 +4 f-block groups
59 praseodymium Pr 0 +1 +2 +3 +4 +5 f-block groups [60][99][100][101]
60 neodymium Nd 0 +2 +3 +4 f-block groups [60][102]
61 promethium Pm +2 +3 f-block groups [103]
62 samarium Sm 0 +1 +2 +3 f-block groups [104]
63 europium Eu 0 +2 +3 f-block groups [60]
64 gadolinium Gd 0 +1 +2 +3 f-block groups [60]
65 terbium Tb 0 +1 +2 +3 +4 f-block groups [60][98][103]
66 dysprosium Dy 0 +2 +3 +4 f-block groups [60][105]
67 holmium Ho 0 +2 +3 f-block groups [60][103]
68 erbium Er 0 +2 +3 f-block groups [60][103]
69 thulium Tm 0 +1 +2 +3 f-block groups [60][98]
70 ytterbium Yb 0 +1 +2 +3 f-block groups [60][98]
71 lutetium Lu 0 +2 +3 3 [60][103]
72 hafnium Hf −2 0 +1 +2 +3 +4 4 [32][64][106]
73 tantalum Ta −3 −1 0 +1 +2 +3 +4 +5 5 [32][66]
74 tungsten W −4 −2 −1 0 +1 +2 +3 +4 +5 +6 6 [32]
75 rhenium Re −3 −1 0 +1 +2 +3 +4 +5 +6 +7 7 [107]
76 osmium Os −4 −2 −1 0 +1 +2 +3 +4 +5 +6 +7 +8 8 [39][108]
77 iridium Ir −3 −2 −1 0 +1 +2 +3 +4 +5 +6 +7 +8 +9 9 [109][110][111][112][113]
78 platinum Pt −3 −2 −1 0 +1 +2 +3 +4 +5 +6 10 [39][114][115]
79 gold Au −3 −2 −1 0 +1 +2 +3 +5 11 [39][116]
80 mercury Hg −2 +1 +2 12 [39][117]
81 thallium Tl −5 −2 −1 +1 +2 +3 13 [18][118][119][120]
82 lead Pb −4 −2 −1 0 +1 +2 +3 +4 14 [18][121][122][123]
83 bismuth Bi −3 −2 −1 0 +1 +2 +3 +4 +5 15 [124][125][126][127][128]
84 polonium Po −2 +2 +4 +5 +6 16 [129]
85 astatine At −1 +1 +3 +5 +7 17
86 radon Rn +2 +6 18 [130][131][132]
87 francium Fr +1 1
88 radium Ra +2 2
89 actinium Ac +3 f-block groups
90 thorium Th −1 +1 +2 +3 +4 f-block groups [133][134][135]
91 protactinium Pa +2 +3 +4 +5 f-block groups [136]
92 uranium U −1 +1 +2 +3 +4 +5 +6 f-block groups [137][138][139]
93 neptunium Np +2 +3 +4 +5 +6 +7 f-block groups [140]
94 plutonium Pu +2 +3 +4 +5 +6 +7 +8 f-block groups [141][142]
95 americium Am +2 +3 +4 +5 +6 +7 f-block groups [143]
96 curium Cm +3 +4 +5 +6 f-block groups [144][145][146][147]
97 berkelium Bk +2 +3 +4 +5 f-block groups [144][145][148][149][150]
98 californium Cf +2 +3 +4 +5 f-block groups [144][145]
99 einsteinium Es +2 +3 +4 f-block groups [151]
100 fermium Fm +2 +3 f-block groups
101 mendelevium Md +2 +3 f-block groups
102 nobelium No +2 +3 f-block groups
103 lawrencium Lr +3 3
104 rutherfordium Rf +4 4
105 dubnium Db +5 5 [152]
106 seaborgium Sg 0 +6 6 [153][154]
107 bohrium Bh +7 7 [155]
108 hassium Hs +8 8 [156]
109 meitnerium Mt 9
110 darmstadtium Ds 10
111 roentgenium Rg 11
112 copernicium Cn +2 12 [157]
113 nihonium Nh 13
114 flerovium Fl 14
115 moscovium Mc 15
116 livermorium Lv 16
117 tennessine Ts 17
118 oganesson Og 18
  1. ↑ H(0) is found in dihydrogen complexes.
  2. ↑ Disodium helide, (Na+)2He(e-)2, has been synthesized at high pressure, see Dong, Xiao; Oganov, Artem R.; Goncharov, Alexander F.; Stavrou, Elissaios; Lobanov, Sergey; Saleh, Gabriele; Qian, Guang-Rui; Zhu, Qiang; Gatti, Carlo; Deringer, Volker L.; Dronskowski, Richard; Zhou, Xiang-Feng; Prakapenka, Vitali B.; Konôpková, Zuzana; Popov, Ivan A.; Boldyrev, Alexander I.; Wang, Hui-Tian (6 February 2017). "A stable compound of helium and sodium at high pressure". Nature Chemistry. 9 (5): 440–445. arXiv:1309.3827. Bibcode:2017NatCh...9..440D. doi:10.1038/nchem.2716. PMID 28430195. S2CID 20459726.
  3. ↑ 3.0 3.1 3.2 3.3 3.4 Na(−1), K(−1), Rb(−1), and Cs(−1) are known in alkalides; the table by Greenwood and Earnshaw shows −1 only for Na and also erroneously for Li; no lithides are described.
  4. ↑ Li(0) atoms have been observed in various small lithium-chloride clusters; see Milovanović, Milan; Veličković, Suzana; Veljkovićb, Filip; Jerosimić, Stanka (October 30, 2017). "Structure and stability of small lithium-chloride LinClm(0,1+) (n ≥ m, n = 1–6, m = 1–3) clusters". Physical Chemistry Chemical Physics. 19 (45): 30481–30497. doi:10.1039/C7CP04181K. PMID 29114648.
  5. ↑ Be(0) has been observed; see "Beryllium(0) Complex Found". Chemistry Europe. 13 June 2016.
  6. ↑ Be(I) has been observed in beryllium monohydride (BeH); see Shayesteh, A.; Tereszchuk, K.; Bernath, P. F.; Colin, R. (2003). "Infrared Emission Spectra of BeH and BeD" (PDF). J. Chem. Phys. 118 (3): 1158. Bibcode:2003JChPh.118.1158S. doi:10.1063/1.1528606. Archived from the original (PDF) on 2007-12-02. Retrieved 2007-12-10. and in [(CAAC)2Be]+• [CAAC = cyclic (alkyl)(amino)carbene], see Wang, Guocang; Walley, Jacob E.; Dickie, Diane E.; Pan, Sudip; Frenking, Gernot; Gilliard Jr., Robert G. (2020). "A Stable, Crystalline Beryllium Radical Cation". J. Am. Chem. Soc. 142 (10): 4560–4. doi:10.1021/jacs.9b13777. PMID 32088963. S2CID 211262005. Retrieved 2020-11-17.
  7. ↑ B(−5) has been observed in Al3BC, see Schroeder, Melanie. "Eigenschaften von borreichen Boriden und Scandium-Aluminium-Oxid-Carbiden" (in German). p. 139.
  8. ↑ B(−1) has been observed in magnesium diboride (MgB2), see Keeler, James; Wothers, Peter (2014). Chemical Structure and Reactivity: An Integrated Approach. Oxford University Press. ISBN 9780199604135.
  9. ↑ B(0) has been observed in diborynes, see Braunschweig, H.; Dewhurst, R. D.; Hammond, K.; Mies, J.; Radacki, K.; Vargas, A. (2012). "Ambient-Temperature Isolation of a Compound with a Boron-Boron Triple Bond". Science. 336 (6087): 1420–1422. Bibcode:2012Sci...336.1420B. doi:10.1126/science.1221138. PMID 22700924. S2CID 206540959.
  10. ↑ Tetrazoles contain a pair of double-bonded nitrogen atoms with oxidation state 0 in the ring. A Synthesis of the parent 1H-tetrazole, CH2N4 (two atoms N(0)) is given in Henry, Ronald A.; Finnegan, William G. (1954). "An Improved Procedure for the Deamination of 5-Aminotetrazole". J. Am. Chem. Soc. 76 (1): 290–291. doi:10.1021/ja01630a086.
  11. ↑ Gold heptafluoride is calculated to be the pentafluoride with a molecular F2 ligand. Himmel, Daniel; Riedel, Sebastian (2007). "After 20 Years, Theoretical Evidence That 'AuF7' Is Actually AuF5•F2". Inorganic Chemistry. 46 (13): 5338–5342. doi:10.1021/ic700431s. PMID 17511450.
  12. ↑ A cluster of elusive SF6+ with helium atoms is known to have fluorine(0) atom as a ligand; see Albertini, Simon; Bergmeister, Stefan; Laimer, Felix; Martini, Paul; Gruber, Elisabeth; Zappa, Fabio; Ončák, Milan; Scheier, Paul; Echt, Olof (2021-04-22). "SF 6 + : Stabilizing Transient Ions in Helium Nanodroplets". The Journal of Physical Chemistry Letters. 12 (17): 4112–4117. doi:10.1021/acs.jpclett.1c01024. ISSN 1948-7185. PMC 8154854. PMID 33886323.
  13. ↑ Ne(0) has been observed in Cr(CO)5Ne. Perutz, Robin N.; Turner, James J. (August 1975). "Photochemistry of the Group 6 hexacarbonyls in low-temperature matrices. III. Interaction of the pentacarbonyls with noble gases and other matrices". Journal of the American Chemical Society. 97 (17): 4791–4800. doi:10.1021/ja00850a001.
  14. ↑ The compound NaCl has been shown in experiments to exists in several unusual stoichiometries under high pressure, including Na3Cl in which contains a layer of sodium(0) atoms; see Zhang, W.; Oganov, A. R.; Goncharov, A. F.; Zhu, Q.; Boulfelfel, S. E.; Lyakhov, A. O.; Stavrou, E.; Somayazulu, M.; Prakapenka, V. B.; Konôpková, Z. (2013). "Unexpected Stable Stoichiometries of Sodium Chlorides". Science. 342 (6165): 1502–1505. arXiv:1310.7674. Bibcode:2013Sci...342.1502Z. doi:10.1126/science.1244989. PMID 24357316. S2CID 15298372.
  15. ↑ Low valent magnesium compounds with Mg(I) have been obtained using bulky ligands; see Green, S. P.; Jones C.; Stasch A. (December 2007). "Stable Magnesium(I) Compounds with Mg-Mg Bonds". Science. 318 (5857): 1754–1757. Bibcode:2007Sci...318.1754G. doi:10.1126/science.1150856. PMID 17991827. S2CID 40657565.
  16. ↑ Mg(0) has been synthesized in a compound containing a Na2Mg22+ cluster coordinated to a bulky organic ligand; see Rösch, B.; Gentner, T. X.; Eyselein, J.; Langer, J.; Elsen, H.; Li, W.; Harder, S. (2021). "Strongly reducing magnesium(0) complexes". Nature. 592 (7856): 717–721. Bibcode:2021Natur.592..717R. doi:10.1038/s41586-021-03401-w. PMID 33911274. S2CID 233447380
  17. ↑ Al(II) has been observed in aluminium(II) oxide (AlO); see Tyte, D.C. (1964). "Red (B2Π–A2σ) Band System of Aluminium Monoxide". Nature. 202 (4930): 383–384. Bibcode:1964Natur.202..383T. doi:10.1038/202383a0. S2CID 4163250, and in dialanes (R2Al—AlR2); see Uhl, Werner (2004). "Organoelement Compounds Possessing Al—Al, Ga—Ga, In—In, and Tl—Tl Single Bonds". Advances in Organometallic Chemistry. 51: 53–108. doi:10.1016/S0065-3055(03)51002-4.
  18. ↑ 18.0 18.1 18.2 18.3 18.4 18.5 18.6 18.7 18.8 Negative oxidation states of p-block metals (Al, Ga, In, Sn, Tl, Pb, Bi, Po) and metalloids (Si, Ge, As, Sb, Te, At) may occur in Zintl phases, see: Riedel, Erwin, ed. (2007). Moderne Anorganische Chemie (in German). p. 259, and "Vorlesung Intermetallische Phasen § 6.2 Binäre Zintl-Phasen" (in German).
  19. ↑ Unstable carbonyl of Al(0) has been detected in reaction of Al2(CH3)6 with carbon monoxide; see Sanchez, Ramiro; Arrington, Caleb; Arrington Jr., C. A. (December 1, 1989). "Reaction of trimethylaluminum with carbon monoxide in low-temperature matrixes". American Chemical Society. 111 (25): 9110-9111. doi:10.1021/ja00207a023. OSTI 6973516.
  20. ↑ Al(−2) has been observed in Sr14[Al4]2[Ge]3, see Wemdorff, Marco; Röhr, Caroline (2007). "Sr14[Al4]2[Ge]3: Eine Zintl-Phase mit isolierten [Ge]4–- und [Al4]8–-Anionen / Sr14[Al4]2[Ge]3: A Zintl Phase with Isolated [Ge]4–- and [Al4]8– Anions". Zeitschrift für Naturforschung B (in German). 62 (10): 1227. doi:10.1515/znb-2007-1001. S2CID 94972243.
  21. ↑ 21.0 21.1 21.2 "New Type of Zero-Valent Tin Compound". Chemistry Europe. 27 August 2016.
  22. ↑ P(0) has been observed, see Wang, Yuzhong; Xie, Yaoming; Wei, Pingrong; King, R. Bruce; Schaefer, Iii; Schleyer, Paul v. R.; Robinson, Gregory H. (2008). "Carbene-Stabilized Diphosphorus". Journal of the American Chemical Society. 130 (45): 14970–1. doi:10.1021/ja807828t. PMID 18937460.
  23. ↑ Chlorine(0) is present as dichlorine in {SnCl62--Cl2}x and {PbCl62--Cl2}x polymeric anion complexes see Usoltsev, Andrey N.; Korobeynikov, Nikita A.; Kolesov, Boris A.; Novikov, Alexander S.; Samsonenko, Denis G.; Fedin, Vladimir P.; Sokolov, Maxim N.; Adonin, Sergey A. (February 24, 2021). "Rule, Not Exclusion: Formation of Dichlorine-Containing Supramolecular Complexes with Chlorometalates(IV)". Inorg. Chem. 60 (6): 4171–4177. doi:10.1021/acs.inorgchem.1c00436. PMID 33626273. S2CID 232047538.
  24. ↑ The equilibrium Cl2O6⇌2ClO3 is mentioned by Greenwood and Earnshaw, but it has been refuted, see Lopez, Maria; Juan E. Sicre (1990). "Physicochemical properties of chlorine oxides. 1. Composition, ultraviolet spectrum, and kinetics of the thermolysis of gaseous dichlorine hexoxide". J. Phys. Chem. 94 (9): 3860–3863. doi:10.1021/j100372a094., and Cl2O6 is actually chlorine(V,VII) oxide. However, ClO3 has been observed, see Grothe, Hinrich; Willner, Helge (1994). "Chlorine Trioxide: Spectroscopic Properties, Molecular Structure, and Photochemical Behavior". Angew. Chem. Int. Ed. 33 (14): 1482–1484. doi:10.1002/anie.199414821.
  25. ↑ Ar(0) has been observed in argon fluorohydride (HArF) and ArCF22+, see Lockyear, J.F.; Douglas, K.; Price, S.D.; Karwowska, M.; et al. (2010). "Generation of the ArCF22+ Dication". Journal of Physical Chemistry Letters. 1: 358. doi:10.1021/jz900274p.
  26. ↑ Ca(I) has been observed; see Krieck, Sven; Görls, Helmar; Westerhausen, Matthias (2010). "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 of the American Chemical Society. 132 (35): 12492–501. doi:10.1021/ja105534w. PMID 20718434.
  27. ↑ 27.0 27.1 27.2 Octacarbonyl complexes isolated of Ca, Sr, Ba have been observed in a neon matrix, but it remains unclear whether these are metal(0) complexes because calculations disagree whether the metal is covalently or ionically bonded to the ligands; see Wu, X.; Zhao, L.; Jin, J.; Pan, S.; Li, W.; Jin, X.; Wang, G.; Zhou, M.; Frenking, G. (2018). "Observation of alkaline earth complexes M(CO)8 (M = Ca, Sr, or Ba) that mimic transition metals". Science. 361 (6405): 912–916. Bibcode:2018Sci...361..912W. doi:10.1126/science.aau0839. PMID 30166489. S2CID 52131470
  28. ↑ Sc(0) has been observed; see F. Geoffrey N. Cloke; Karl Khan & Robin N. Perutz (1991). "η-Arene complexes of scandium(0) and scandium(II)". J. Chem. Soc., Chem. Commun. (19): 1372–1373. doi:10.1039/C39910001372.
  29. ↑ Sc(I) has been observed; see Polly L. Arnold; F. Geoffrey; N. Cloke; Peter B. Hitchcock & John F. Nixon (1996). "The First Example of a Formal Scandium(I) Complex: Synthesis and Molecular Structure of a 22-Electron Scandium Triple Decker Incorporating the Novel 1,3,5-Triphosphabenzene Ring". J. Am. Chem. Soc. 118 (32): 7630–7631. doi:10.1021/ja961253o.
  30. ↑ Sc(II) has been observed; see Woen, David H.; Chen, Guo P.; Ziller, Joseph W.; Boyle, Timothy J.; Furche, Filipp; Evans, William J. (January 2017). "Solution Synthesis, Structure, and CO Reduction Reactivity of a Scandium(II) Complex". Angewandte Chemie International Edition. 56 (8): 2050–2053. doi:10.1002/anie.201611758. PMID 28097771.
  31. ↑ Ti(I) has been observed in [Ti(η6-1,3,5-C6H3iPr3)2][BAr4] (Ar = C6H5, p-C6H4F, 3,5-C6H3(CF3)2); see Calderazzo, Fausto; Ferri, Isabella; Pampaloni, Guido; Englert, Ulli; Green, Malcolm L. H. (1997). "Synthesis of [Ti(η6-1,3,5-C6H3iPr3)2][BAr4] (Ar = C6H5, p-C6H4F, 3,5-C6H3(CF3)2), the First Titanium(I) Derivatives". Organometallics. 16 (14): 3100–3101. doi:10.1021/om970155o.
  32. ↑ 32.00 32.01 32.02 32.03 32.04 32.05 32.06 32.07 32.08 32.09 32.10 32.11 Ti(−2), V(−3), Cr(−4), Co(−3), Zr(−2), Nb(−3), Mo(−4), Ru(−2), Rh(−3), Hf(−2), Ta(−3), and W(−4) occur in anionic binary metal carbonyls; see Christian Bach (January 1999). Carbonylkomplexe der Platinmetalle [Carbonyl complexes of the platinum metals] (Doctor of Science) (in German). p. 4.; Werner, Helmut (2008). Landmarks in Organo-Transition Metal Chemistry: A Personal View. Springer Science & Business Media. pp. 97–100. ISBN 978-0-387-09848-7.; Haiduc, Ionel; Zuckerman, Jerry J. (2011). Basic Organometallic Chemistry: Containing Comprehensive Bibliography. Walter de Gruyter. p. 239. ISBN 978-0-89925-006-9.
  33. ↑ Ti(−1) has been reported in [Ti(bipy)3]−, but was later shown to be Ti(+3); see Bowman, A. C.; England, J.; Sprouls, S.; Weihemüller, T.; Wieghardt, K. (2013). "Electronic structures of homoleptic [tris(2,2'-bipyridine)M]n complexes of the early transition metals (M = Sc, Y, Ti, Zr, Hf, V, Nb, Ta; n = 1+, 0, 1-, 2-, 3-): an experimental and density functional theoretical study". Inorganic Chemistry. 52 (4): 2242–2256. doi:10.1021/ic302799s. PMID 23387926. However, Ti(−1) occurs in [Ti(η-C6H6]− and [Ti(η-C6H5CH3)]−, see Bandy, J. A.; Berry, A.; Green, M. L. H.; Perutz, R. N.; Prout, K.; Verpeautz, J.-N. (1984). "Synthesis of anionic sandwich compounds: [Ti(η-C6H5R)2]– and the crystal structure of [K(18-crown-6)(µ-H)Mo(η-C5H5)2]". Inorganic Chemistry. 52 (4): 729–731. doi:10.1039/C39840000729.
  34. ↑ Jilek, Robert E.; Tripepi, Giovanna; Urnezius, Eugenijus; Brennessel, William W.; Young, Victor G. Jr.; Ellis, John E. (2007). "Zerovalent titanium–sulfur complexes. Novel dithiocarbamato derivatives of Ti(CO)6: [Ti(CO)4(S2CNR2)]−". Chem. Commun. (25): 2639–2641. doi:10.1039/B700808B. PMID 17579764.
  35. ↑ Mn(–3) and Mn(–1) occurs in Mn(NO)3(CO) and HMn(CO)5 respectively; see Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 1046. ISBN 978-0-08-037941-8.
  36. ↑ Mn(–2) has been described erroneously by Greenwood as [MnPc]2–; for a correct explanation, see Gcineka Mbambisa; Prudence Tau; Edith Antunes; Tebello Nyokong (2007). "Synthesis and electrochemical properties of purple manganese(III) and red titanium(IV) phthalocyanine complexes octa-substituted at non-peripheral positions with pentylthio groups". Polyhedron. 26 (18): 5355–5364. doi:10.1016/j.poly.2007.08.007.
  37. ↑ Fe(VII) has been observed in [FeO4]−; see Lu, Jun-Bo; Jian, Jiwen; Huang, Wei; Lin, Hailu; Zhou, Mingfei (2016). "Experimental and theoretical identification of the Fe(VII) oxidation state in FeO4−". Physical Chemistry Chemical Physics. 18 (45): 31125–31131. Bibcode:2016PCCP...1831125L. doi:10.1039/C6CP06753K. PMID 27812577.
  38. ↑ Fe(VIII) has been reported; see Yurii D. Perfiliev; Virender K. Sharma (2008). "Higher Oxidation States of Iron in Solid State: Synthesis and Their Mössbauer Characterization – Ferrates – ACS Symposium Series (ACS Publications)". Platinum Metals Review. 48 (4): 157–158. doi:10.1021/bk-2008-0985.ch007. However, its existence has been disputed.
  39. ↑ 39.00 39.01 39.02 39.03 39.04 39.05 39.06 39.07 39.08 39.09 Fe(−4), Ru(−4), and Os(−4) have been observed in metal-rich compounds containing octahedral complexes [MIn6−xSnx]; Pt(−3) (as a dimeric anion [Pt–Pt]6−), Cu(−2), Zn(−2), Ag(−2), Cd(−2), Au(−2), and Hg(−2) have been observed (as dimeric and monomeric anions; dimeric ions were initially reported to be [T–T]2− for Zn, Cd, Hg, but later shown to be [T–T]4− for all these elements) in La2Pt2In, La2Cu2In, Ca5Au3, Ca5Ag3, Ca5Hg3, Sr5Cd3, Ca5Zn3(structure (AE2+)5(T–T)4−T2−⋅4e−), Yb3Ag2, Ca5Au4, and Ca3Hg2; Au(–3) has been observed in ScAuSn and in other 18-electron half-Heusler compounds. See Changhoon Lee; Myung-Hwan Whangbo (2008). "Late transition metal anions acting as p-metal elements". Solid State Sciences. 10 (4): 444–449. Bibcode:2008SSSci..10..444K. doi:10.1016/j.solidstatesciences.2007.12.001. and Changhoon Lee; Myung-Hwan Whangbo; Jürgen Köhler (2010). "Analysis of Electronic Structures and Chemical Bonding of Metal-rich Compounds. 2. Presence of Dimer (T–T)4– and Isolated T2– Anions in the Polar Intermetallic Cr5B3-Type Compounds AE5T3 (AE = Ca, Sr; T = Au, Ag, Hg, Cd, Zn)". Zeitschrift für Anorganische und Allgemeine Chemie. 636 (1): 36–40. doi:10.1002/zaac.200900421.
  40. ↑ Ni(−2) has been observed in Li2[Ni(1,5-COD)2], see Jonas, Klaus (1975). "Dilithium-Nickel-Olefin Complexes. Novel Bimetal Complexes Containing a Transition Metal and a Main Group Metal". Angew. Chem. Int. Ed. 14 (11): 752–753. doi:10.1002/anie.197507521. and Ellis, John E. (2006). "Adventures with Substances Containing Metals in Negative Oxidation States". Inorganic Chemistry. 45 (8): 3167–86. doi:10.1021/ic052110i. PMID 16602773.
  41. ↑ Cu(0) has been observed in Cu(tris[2-(diisopropylphosphino)- phenyl]borane), see Moret, Marc-Etienne; Zhang, Limei; Peters, Jonas C. (2013). "A Polar Copper–Boron One-Electron σ-Bond". J. Am. Chem. Soc. 135 (10): 3792–3795. doi:10.1021/ja4006578. PMID 23418750.
  42. ↑ Zn(0) has been observed; see Singh, Amit Pratap; Samuel, Prinson P.; Roesky, Herbert W.; Schwarzer, Martin C.; Frenking, Gernot; Sidhu, Navdeep S.; Dittrich, Birger (2013). "A Singlet Biradicaloid Zinc Compound and Its Nonradical Counterpart". J. Am. Chem. Soc. 135 (19): 7324–9. doi:10.1021/ja402351x. PMID 23600486. and Soleilhavoup, Michèle; Bertrand, Guy (2015). "Cyclic (Alkyl)(Amino)Carbenes (CAACs): Stable Carbenes on the Rise". Acc. Chem. Res. 48 (2): 256–266. doi:10.1021/ar5003494. PMID 25515548.
  43. ↑ Zn(I) has been observed in decamethyldizincocene (Zn2(η5–C5Me5)2); see Resa, I.; Carmona, E.; Gutierrez-Puebla, E.; Monge, A. (2004). "Decamethyldizincocene, a Stable Compound of Zn(I) with a Zn-Zn Bond". Science. 305 (5687): 1136–8. Bibcode:2004Sci...305.1136R. doi:10.1126/science.1101356. PMID 15326350. S2CID 38990338.
  44. ↑ Zn(III) has been predicted to be stable in compounds with highly stabilized borane-based trianions, but no Zn(III) candidates are known experimentally; see Hong Fang; Huta Banjade; Deepika; Puru Jena (2021). "Realization of the Zn3+ oxidation state". Nanoscale. 13 (33): 14041–14048. doi:10.1039/D1NR02816B. PMID 34477685. S2CID 237400349.
  45. ↑ Ga(−2), Ga(−4), and Ga(−5) have been observed in the magnesium gallides MgGa, Mg2Ga, and Mg5Ga2, respectively; see Patrick Hofmann. "Colture. Ein Programm zur interaktiven Visualisierung von Festkörperstrukturen sowie Synthese, Struktur und Eigenschaften von binären und ternären Alkali- und Erdalkalimetallgalliden" (PDF) (in German). p. 72.
  46. ↑ Ga(−3) has been observed in LaGa, see Dürr, Ines; Bauer, Britta; Röhr, Caroline (2011). "Lanthan-Triel/Tetrel-ide La(Al,Ga)x(Si,Ge)1-x. Experimentelle und theoretische Studien zur Stabilität intermetallischer 1:1-Phasen" (PDF). Z. Naturforsch. (in German). 66b: 1107–1121.
  47. ↑ Ga(0) has been observed in Gallium monoiodide among other gallium's oxidation states
  48. ↑ Ge(−1), Ge(−2), and Ge(−3) have been observed in germanides; see Holleman, Arnold F.; Wiberg, Egon; Wiberg, Nils (1995). "Germanium". Lehrbuch der Anorganischen Chemie (in German) (101 ed.). Walter de Gruyter. pp. 953–959. ISBN 978-3-11-012641-9.
  49. ↑ As(0) has been observed; see Abraham, Mariham Y.; Wang, Yuzhong; Xie, Yaoming; Wei, Pingrong; Shaefer III, Henry F.; Schleyer, P. von R.; Robinson, Gregory H. (2010). "Carbene Stabilization of Diarsenic: From Hypervalency to Allotropy". Chemistry: A European Journal. 16 (2): 432–5. doi:10.1002/chem.200902840. PMID 19937872.
  50. ↑ As(I) has been observed in arsenic(I) iodide (AsI); see Ellis, Bobby D.; MacDonald, Charles L. B. (2004). "Stabilized Arsenic(I) Iodide: A Ready Source of Arsenic Iodide Fragments and a Useful Reagent for the Generation of Clusters". Inorganic Chemistry. 43 (19): 5981–6. doi:10.1021/ic049281s. PMID 15360247.
  51. ↑ As(IV) has been observed in arsenic(IV) hydroxide (As(OH)4) and HAsO−
    ; see Kläning, Ulrik K.; Bielski, Benon H. J.; Sehested, K. (1989). "Arsenic(IV). A pulse-radiolysis study". Inorganic Chemistry. 28 (14): 2717–24. doi:10.1021/ic00313a007.
  52. ↑ Se(−1) has been observed in diselenides(2−) (Se22−).
  53. ↑ A Se(0) atom has been identified using DFT in [ReOSe(2-pySe)3]; see Cargnelutti, Roberta; Lang, Ernesto S.; Piquini, Paulo; Abram, Ulrich (2014). "Synthesis and structure of [ReOSe(2-Se-py)3]: A rhenium(V) complex with selenium(0) as a ligand". Inorganic Chemistry Communications. 45: 48–50. doi:10.1016/j.inoche.2014.04.003. ISSN 1387-7003.
  54. ↑ Se(I) has been observed in selenium(I) chloride (Se2Cl2); see "Selenium: Selenium(I) chloride compound data". WebElements.com. Retrieved 2007-12-10.
  55. ↑ Se(III) has been observed in Se2NBr3; see Lau, Carsten; Neumüller, Bernhard; Vyboishchikov, Sergei F.; Frenking, Gernot; Dehnicke, Kurt; Hiller, Wolfgang; Herker, Martin (1996). "Se2NBr3, Se2NCl5, Se2NCl−6: New Nitride Halides of Selenium(III) and Selenium(IV)". Chemistry: A European Journal. 2 (11): 1393–1396. doi:10.1002/chem.19960021108.
  56. ↑ Se(V) has been observed in SeO−
    3     and HSeO2−
    4    ; see Kläning, Ulrik K.; Sehested, K. (1986). "Selenium(V). A pulse radiolysis study". Inorganic Chemistry. 90 (21): 5460–4. doi:10.1021/j100412a112.
  57. ↑ Bromine(0) is present as an adduct in a copper-bromine complex, see Okrut, Alexander; Feldmann, Claus (5 March 2008). "{[P(o-tolyl)3]Br}2[Cu2Br6](Br2)—An Ionic Compound Containing Molecular Bromine". Inorganic Chemistry. 47 (8): 3084–3087. doi:10.1021/ic7021038. PMID 18318489.
  58. ↑ Br(II) is known to occur in bromine monoxide radical; see [1]
  59. ↑ Sr(I) has been observed in strontium monofluoride (SrF); see Colarusso, P.; Guo, B.; Zhang, K.-Q.; Bernath, P.F. (1996). "High-Resolution Infrared Emission Spectrum of Strontium Monofluoride" (PDF). Journal of Molecular Spectroscopy. 175 (1): 158–171. Bibcode:1996JMoSp.175..158C. doi:10.1006/jmsp.1996.0019. Archived from the original (PDF) on 2012-03-08.
  60. ↑ 60.00 60.01 60.02 60.03 60.04 60.05 60.06 60.07 60.08 60.09 60.10 60.11 60.12 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 Cloke, F. Geoffrey N. (1993). "Zero Oxidation State Compounds of Scandium, Yttrium, and the Lanthanides". Chem. Soc. Rev. 22: 17–24. doi:10.1039/CS9932200017. and Arnold, Polly L.; Petrukhina, Marina A.; Bochenkov, Vladimir E.; Shabatina, Tatyana I.; Zagorskii, Vyacheslav V.; Cloke (2003-12-15). "Arene complexation of Sm, Eu, Tm and Yb atoms: a variable temperature spectroscopic investigation". Journal of Organometallic Chemistry. 688 (1–2): 49–55. doi:10.1016/j.jorganchem.2003.08.028.
  61. ↑ Y(I) has been observed in yttrium(I) bromide (YBr); see Kaley A. Walker; Michael C. L. Gerry (1998). "The pure rotational spectrum of yttrium monobromide". The Journal of Chemical Physics. 109 (13): 5439–5445. doi:10.1063/1.477162.
  62. ↑ Y(II) has been observed in [(18-crown-6)K][(C5H4SiMe3)3Y]; see MacDonald, M. R.; Ziller, J. W.; Evans, W. J. (2011). "Synthesis of a Crystalline Molecular Complex of Y2+, [(18-crown-6)K][(C5H4SiMe3)3Y]". J. Am. Chem. Soc. 133 (40): 15914–17. doi:10.1021/ja207151y. PMID 21919538.
  63. ↑ Zr(−1) has been reported in [Zr(bipy)3]− (see Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 960. ISBN 978-0-08-037941-8. and Holleman, Arnold F.; Wiberg, Egon; Wiberg, Nils (1995). "Zirconium". Lehrbuch der Anorganischen Chemie (in German) (101 ed.). Walter de Gruyter. p. 1413. ISBN 978-3-11-012641-9.), but was later shown to be Zr(+4); see Bowman, A. C.; England, J.; Sprouls, S.; Weihemüller, T.; Wieghardt, K. (2013). "Electronic structures of homoleptic [tris(2,2'-bipyridine)M]n complexes of the early transition metals (M = Sc, Y, Ti, Zr, Hf, V, Nb, Ta; n = 1+, 0, 1-, 2-, 3-): an experimental and density functional theoretical study". Inorganic Chemistry. 52 (4): 2242–56. doi:10.1021/ic302799s. PMID 23387926.
  64. ↑ 64.0 64.1 Zr(0) and Hf(0) occur in (η6-(1,3,5-tBu)3C6H3)2M (M=Zr, Hf) and [(η5-C5R5M(CO)4]−, see Chirik, P. J.; Bradley, C. A. (2007). "4.06 - Complexes of Zirconium and Hafnium in Oxidation States 0 to ii". Comprehensive Organometallic Chemistry III. From Fundamentals to Applications. Vol. 4. Elsevier Ltd. pp. 697–739. doi:10.1016/B0-08-045047-4/00062-5. ISBN 9780080450476.
  65. ↑ Complexes of Nb(0) and Ta(0) have been observed, see Holleman, Arnold F.; Wiberg, Egon; Wiberg, Nils (2003). "4.5.7. Niobium(0) and Tantalum(0)". In J. A. McCleverty; T.J. Meyer (eds.). Comprehensive Coordination Chemistry II: From Biology to Nanotechnology. Vol. 4 (2 ed.). Newnes. pp. 297–299. ISBN 978-0-08-091316-2.
  66. ↑ 66.0 66.1 Nb(I) and Ta(I) occur in CpNb(CO)4 and CpTa(CO)4, see Holleman, Arnold F.; Wiberg, Egon; Wiberg, Nils (1995). "Tantal". Lehrbuch der Anorganischen Chemie (in German) (101 ed.). Walter de Gruyter. p. 1430. ISBN 978-3-11-012641-9. and King, R. Bruce (1969). Transition-Metal Organometallic Chemistry: An Introduction. Academic Press. p. 11. ISBN 978-0-32-315996-8.
  67. ↑ Tc(–1) occurs in HTc(CO)5; see John E. Ellis (2003). "Metal Carbonyl Anions:  from [Fe(CO)4]2- to [Hf(CO)6]2- and Beyond†". Organometallics. 22 (17): 3322–3338. doi:10.1021/om030105l. Tc(–3) is erroneously reported by Greenwood.
  68. ↑ George, G.N.; Klein, S.I.; Nixon, J.F. (1984). "Electron paramagnetic resonance spectroscopic studies on the zero-valent rhodium complex [Rh(P(OPri)3)4] at X-and Q-band frequencies". Chemical Physics Letters. 108 (6): 627–630. Bibcode:1984CPL...108..627G. doi:10.1016/0009-2614(84)85069-1.
  69. ↑ Rh(VII) is known in the RhO3+ cation, see Da Silva Santos, Mayara; Stüker, Tony; Flach, Max; Ablyasova, Olesya S.; Timm, Martin; von Issendorff, Bernd; Hirsch, Konstantin; Zamudio‐Bayer, Vicente; Riedel, Sebastian; Lau, J. Tobias (2022). "The Highest Oxidation State of Rhodium: Rhodium(VII) in [RhO3]+". Angew. Chem. Int. Ed. 61 (38). doi:10.1002/anie.202207688. PMID 35818987. S2CID 250455408.
  70. ↑ Pd(I) has been observed; see Crabtree, R. H. (2002). "CHEMISTRY: A New Oxidation State for Pd?". Science. 295 (5553): 288–289. doi:10.1126/science.1067921. PMID 11786632. S2CID 94579227.
  71. ↑ Pd(III) has been observed; see Powers, D. C.; Ritter, T. (2011). "Palladium(III) in Synthesis and Catalysis" (PDF). Higher Oxidation State Organopalladium and Platinum Chemistry. Topics in Organometallic Chemistry. Vol. 35. pp. 129–156. Bibcode:2011hoso.book..129P. doi:10.1007/978-3-642-17429-2_6. ISBN 978-3-642-17428-5. PMC 3066514. PMID 21461129. Archived from the original (PDF) on June 12, 2013.
  72. ↑ Palladium(V) has been identified in complexes with organosilicon compounds containing pentacoordinate palladium; see Shimada, Shigeru; Li, Yong-Hua; Choe, Yoong-Kee; Tanaka, Masato; Bao, Ming; Uchimaru, Tadafumi (2007). "Multinuclear palladium compounds containing palladium centers ligated by five silicon atoms". Proceedings of the National Academy of Sciences. 104 (19): 7758–7763. doi:10.1073/pnas.0700450104. PMC 1876520. PMID 17470819.
  73. ↑ Palladium(VI) has been claimed to exist in Dagani, RON (2002). "New Palladium Oxidation State?". Chem. Eng. News. 80 (2): 8. doi:10.1021/cen-v080n002.p008., but this has been refuted showing it is a Palladium(II).
  74. ↑ The Ag− ion has been observed in metal ammonia solutions: see Tran, N. E.; Lagowski, J. J. (2001). "Metal Ammonia Solutions: Solutions Containing Argentide Ions". Inorganic Chemistry. 40 (5): 1067–68. doi:10.1021/ic000333x.
  75. ↑ Ag(0) has been observed in carbonyl complexes in low-temperature matrices: see McIntosh, D.; Ozin, G. A. (1976). "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". J. Am. Chem. Soc. 98 (11): 3167–75. doi:10.1021/ja00427a018. Also, Ag(0) has been observed in [Ag4py2]n, see Hoi Ri Moon; Cheol Ho Choi; Myunghyun Paik Suh (2008). "A Stair-Shaped Molecular Silver(0) Chain". Angewandte Chemie International Edition. 47 (44): 8390–93. doi:10.1002/anie.200803465. PMID 18830949.
  76. ↑ Cd(I) has been observed in cadmium(I) tetrachloroaluminate (Cd2(AlCl4)2); see Holleman, Arnold F.; Wiberg, Egon; Wiberg, Nils (1985). "Cadmium". Lehrbuch der Anorganischen Chemie (in German) (91–100 ed.). Walter de Gruyter. pp. 1056–1057. ISBN 978-3-11-007511-3.
  77. ↑ In(–5) has been observed in La3InGe, see Guloy, A. M.; Corbett, J. D. (1996). "Synthesis, Structure, and Bonding of Two Lanthanum Indium Germanides with Novel Structures and Properties". Inorganic Chemistry. 35 (9): 2616–22. doi:10.1021/ic951378e. PMID 11666477.
  78. ↑ In(−2) has been observed in Na2In, see [2], p. 69.
  79. ↑ Unstable In(0) carbonyls and clusters have been detected, see [3], p. 6.
  80. ↑ Sn(−3) has been observed in [Sn2]6−, e.g. in (Ba2)4+(Mg4)8+Sn4−(Sn2)6−Sn2− (with square (Sn2−)n sheets), see Papoian, Garegin A.; Hoffmann, Roald (2000). "Hypervalent Bonding in One, Two, and Three Dimensions: Extending the Zintl–Klemm Concept to Nonclassical Electron-Rich Networks". Angew. Chem. Int. Ed. 2000 (39): 2408–2448. doi:10.1002/1521-3773(20000717)39:14<2408::aid-anie2408>3.0.co;2-u. PMID 10941096. Retrieved 2015-02-23.
  81. ↑ Sn(I) and Sn(III) have been observed in organotin compounds
  82. ↑ Sb(−2) has been observed in [Sb2]4−, e.g. in RbBa4[Sb2][Sb][O], see Boss, Michael; Petri, Denis; Pickhard, Frank; Zönnchen, Peter; Röhr, Caroline (2005). "Neue Barium-Antimonid-Oxide mit den Zintl-Ionen [Sb]3−, [Sb2]4− und 1∞[Sbn]n− / New Barium Antimonide Oxides containing Zintl Ions [Sb]3−, [Sb2]4− and 1∞[Sbn]n−". Zeitschrift für Anorganische und Allgemeine Chemie (in German). 631 (6–7): 1181–1190. doi:10.1002/zaac.200400546.
  83. ↑ Sb(0) has been observed, see Anastas Sidiropoulos (2019). "Studies of N-heterocyclic Carbene (NHC) Complexes of the Main Group Elements" (PDF). p. 39. doi:10.4225/03/5B0F4BDF98F60. S2CID 132399530.
  84. ↑ Sb(I) and Sb(II) have been observed in organoantimony compounds; for Sb(I), see Šimon, Petr; de Proft, Frank; Jambor, Roman; Růžička, Aleš; Dostál, Libor (2010). "Monomeric Organoantimony(I) and Organobismuth(I) Compounds Stabilized by an NCN Chelating Ligand: Syntheses and Structures". Angewandte Chemie International Edition. 49 (32): 5468–5471. doi:10.1002/anie.201002209. PMID 20602393.
  85. ↑ Sb(IV) has been observed in [SbCl
    6    ]2−, see Nobuyoshi Shinohara; Masaaki Ohsima (2000). "Production of Sb(IV) Chloro Complex by Flash Photolysis of the Corresponding Sb(III) and Sb(V) Complexes in CH3CN and CHCl3". Bulletin of the Chemical Society of Japan. 73 (7): 1599–1604. doi:10.1246/bcsj.73.1599.
  86. ↑ Te(0) has been observed in tellurolates.
  87. ↑ Te(I) has been observed in tellurium iodide (TeI), see "Tellurium: tellurium iodide". WebElements.com. Retrieved 2015-02-23.
  88. ↑ Te(III) has been observed in [Te(N(SiMe3)2)2]+, see Heinze, Thorsten; Roesky, Herbert W.; Pauer, Frank; Stalke, Dietmar; Sheldrick, George M. (1991). "Synthesis and Structure of the First Tellurium(III) Radical Cation". Angewandte Chemie International Edition. 30 (12): 1678. doi:10.1002/anie.199116771. Retrieved 2015-02-23.
  89. ↑ Te(V) is mentioned by Greenwood and Earnshaw, but they do not give any example of a Te(V) compound. What was long thought to be ditellurium decafluoride (Te2F10) is actually bis(pentafluorotelluryl) oxide, F5TeOTeF5: see Watkins, P. M. (1974). "Ditellurium decafluoride - A Continuing Myth". Journal of Chemical Education. 51 (9): 520–521. Bibcode:1974JChEd..51..520W. doi:10.1021/ed051p520. However, Te(V) has been observed in HTeO−
    , TeO−
    , HTeO−
    2    , and TeO−
    3    ; see Kläning, Ulrik K.; Sehested, K. (2001). "Tellurium(V). A Pulse Radiolysis Study". The Journal of Physical Chemistry A. 105 (27): 6637–45. Bibcode:2001JPCA..105.6637K. doi:10.1021/jp010577i.
  90. ↑ Iodine(0) appears as I2 in polymeric {Sb2I93--I2}x and {Bi2I93--I2}x polymeric complex anions: see Korobeynikov, Nikita A; Usoltsev, Andrey N; Abramov, Pavel A; Sokolov, Maxim N; Adonin, Sergey A (2 Dec 2022). "One-Dimensional Iodoantimonate(III) and Iodobismuthate(III) Supramolecular Hybrids with Diiodine: Structural Features, Stability and Optical Properties". Molecules. 27 (23): 8487. doi:10.3390/molecules27238487. PMC 9735928. PMID 36500578.
  91. ↑ I(II) is known to exist in monoxide (IO); see Nikitin, I V (31 August 2008). "Halogen monoxides". Russian Chemical Reviews. 77 (8): 739–749. Bibcode:2008RuCRv..77..739N. doi:10.1070/RC2008v077n08ABEH003788. S2CID 250898175.
  92. ↑ I(IV) has been observed in iodine dioxide (IO2); see Pauling, Linus (1988). "Oxygen Compounds of Nonmetallic Elements". General Chemistry (3rd ed.). Dover Publications, Inc. p. 259. ISBN 978-0-486-65622-9.
  93. ↑ I(VI) has been observed in IO3, IO42−, H5IO6−, H2IO52−, H4IO62−, and HIO53−; see Kläning, Ulrik K.; Sehested, Knud; Wolff, Thomas (1981). "Laser flash photolysis and pulse radiolysis of iodate and periodate in aqueous solution. Properties of iodine(VI)". J. Chem. Soc., Faraday Trans. 1. 77 (7): 1707–18. doi:10.1039/F19817701707.
  94. ↑ Xe compounds: see Xenon
  95. ↑ Xe(0) has been observed in tetraxenonogold(II) (AuXe42+).
  96. ↑ Xe(I) has been reported in xenon hexafluoroplatinate and xenon hexafluororhodate (see Pauling, Linus (1988). General Chemistry (3rd ed.). Dover Publications, Inc. p. 250. ISBN 978-0-486-65622-9.), however these compounds were later found to contain Xe(II).
  97. ↑ Ba(I) has been observed in barium monofluoride (BaF); see Colarusso, P.; Guo, B.; Zhang, K.-Q.; Bernath, P.F. (1995). "High-Resolution Fourier Transform Infrared Emission Spectrum of Barium Monofluoride" (PDF). Journal of Molecular Spectroscopy. 170 (1): 59. Bibcode:1996JMoSp.175..158C. doi:10.1006/jmsp.1996.0019. Archived from the original (PDF) on 2005-03-10.
  98. ↑ 98.0 98.1 98.2 98.3 La(I), Pr(I), Tb(I), Tm(I), and Yb(I) have been observed in MB8− clusters; see Li, Wan-Lu; Chen, Teng-Teng; Chen, Wei-Jia; Li, Jun; Wang, Lai-Sheng (2021). "Monovalent lanthanide(I) in borozene complexes". Nature Communications. 12 (1): 6467. doi:10.1038/s41467-021-26785-9. PMC 8578558. PMID 34753931.
  99. ↑ Pr(I) has been observed in [PrB4]−; see Chen, Xin; Chen, Teng-Teng; Li, Wang-Lu; Lu, Jun-Bo; Zhao, Li-Juan; Jian, Tian; Hu, Han-Shi; Wang, Lai-Sheng; Li, Jun (2018-12-13). "Lanthanides with Unusually Low Oxidation States in the PrB3– and PrB4– Boride Clusters". Inorganic Chemistry. 58 (1): 411–418. doi:10.1021/acs.inorgchem.8b02572. PMID 30543295. S2CID 56148031.
  100. ↑ Pr(V) has been observed in [PrO2]+; see Zhang, Qingnan; Hu, Shu-Xian; Qu, Hui; Su, Jing; Wang, Guanjun; Lu, Jun-Bo; Chen, Mohua; Zhou, Mingfei; Li, Jun (2016-06-06). "Pentavalent Lanthanide Compounds: Formation and Characterization of Praseodymium(V) Oxides". Angewandte Chemie International Edition. 55 (24): 6896–6900. doi:10.1002/anie.201602196. ISSN 1521-3773. PMID 27100273.
  101. ↑ Hu, Shu-Xian; Jian, Jiwen; Su, Jing; Wu, Xuan; Li, Jun; Zhou, Mingfei (2017). "Pentavalent lanthanide nitride-oxides: NPrO and NPrO− complexes with N≡Pr triple bonds". Chemical Science. 8 (5): 4035–4043. doi:10.1039/C7SC00710H. ISSN 2041-6520. PMC 5434915. PMID 28580119.
  102. ↑ Nd(IV) has been observed in unstable solid state compounds; see Template:Holleman&Wiberg
  103. ↑ 103.0 103.1 103.2 103.3 103.4 All the lanthanides (La–Lu) in the +2 oxidation state have been observed (except La, Gd, Lu) in dilute, solid solutions of dihalides of these elements in alkaline earth dihalides (see Template:Holleman&Wiberg) and (except Pm) in organometallic molecular complexes, see Lanthanides Topple Assumptions and Meyer, G. (2014). "All the Lanthanides Do It and Even Uranium Does Oxidation State +2". Angewandte Chemie International Edition. 53 (14): 3550–51. doi:10.1002/anie.201311325. PMID 24616202.. Additionally, all the lanthanides (La–Lu) form dihydrides (LnH2), dicarbides (LnC2), monosulfides (LnS), monoselenides (LnSe), and monotellurides (LnTe), but for most elements these compounds have Ln3+ ions with electrons delocalized into conduction bands, e. g. Ln3+(H−)2(e−).
  104. ↑ SmB6- cluster anion has been reported and contains Sm in rare oxidation state of +1; see Paul, J. Robinson; Xinxing, Zhang; Tyrel, McQueen; Kit, H. Bowen; Anastassia, N. Alexandrova (2017). "SmB6– Cluster Anion: Covalency Involving f Orbitals". J. Phys. Chem. A 2017, 121, 8, 1849–1854. 121 (8): 1849–1854. doi:10.1021/acs.jpca.7b00247. PMID 28182423..
  105. ↑ Dy(IV) has been observed in unstable solid state compounds; see Template:Holleman&Wiberg
  106. ↑ Hf(I) has been observed in hafnium monobromide (HfBr), see Marek, G.S.; Troyanov, S.I.; Tsirel'nikov, V.I. (1979). "Кристаллическое строение и термодинамические характеристики монобромидов циркония и гафния / Crystal structure and thermodynamic characteristics of monobromides of zirconium and hafnium". Журнал неорганической химии / Russian Journal of Inorganic Chemistry (in Russian). 24 (4): 890–893.
  107. ↑ Re(–3) and Re(–1) occurs in Na3[Re(CO)4] and HRe(CO)5 respectively; see Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 1046. ISBN 978-0-08-037941-8.
  108. ↑ Os(−1) has been observed in Na[Os(CO)
    13    ]; see Krause, J.; Siriwardane, Upali; Salupo, Terese A.; Wermer, Joseph R.; Knoeppel, David W.; Shore, Sheldon G. (1993). "Preparation of [Os3(CO)11]2− and its reactions with Os3(CO)12; structures of [Et4N] [HOs3(CO)11] and H2OsS4(CO)". Journal of Organometallic Chemistry. 454 (1–2): 263–271. doi:10.1016/0022-328X(93)83250-Y. and Carter, Willie J.; Kelland, John W.; Okrasinski, Stanley J.; Warner, Keith E.; Norton, Jack R. (1982). "Mononuclear hydrido alkyl carbonyl complexes of osmium and their polynuclear derivatives". Inorganic Chemistry. 21 (11): 3955–3960. doi:10.1021/ic00141a019.
  109. ↑ Ir(−3) has been observed in Ir(CO)33−; see Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 1117. ISBN 978-0-08-037941-8.
  110. ↑ Ir(–2) has been observed in IrVO2–; see Le-Shi Chen; Yun-Zhu Liu; Jiao-Jiao Chen; Si-Dun Wang; Tong-Mei Ma; Xiao-Na Li; Sheng-Gui He (2022). "Water–Gas Shift Catalyzed by Iridium–Vanadium Oxide Clusters IrVO2– with Iridium in a Rare Oxidation State of −II". The Journal of Physical Chemistry A. 126 (32): 5294–5301. doi:10.1021/acs.jpca.2c03974.
  111. ↑ Ir(VII) has been observed in [(η2-O2)IrO2]+; see C&EN: Iridium dressed to the nines.
  112. ↑ Ir(VIII) has been observed in iridium tetroxide (IrO4); see Gong, Yu; Zhou, Mingfei; Kaupp, Martin; Riedel, Sebastian (2009). "Formation and Characterization of the Iridium Tetroxide Molecule with Iridium in the Oxidation State +VIII". Angewandte Chemie International Edition. 48 (42): 7879–7883. doi:10.1002/anie.200902733. PMID 19593837.
  113. ↑ Ir(IX) has been observed in IrO+
    4    ; see Wang, Guanjun; Zhou, Mingfei; Goettel, James T.; Schrobilgen, Gary G.; Su, Jing; Li, Jun; Schlöder, Tobias; Riedel, Sebastian (21 August 2014). "Identification of an iridium-containing compound with a formal oxidation state of IX". Nature. 514 (7523): 475–477. Bibcode:2014Natur.514..475W. doi:10.1038/nature13795. PMID 25341786. S2CID 4463905.
  114. ↑ Pt(−1) and Pt(−2) have been observed in the barium platinides BaPt and Ba2Pt, respectively: see Karpov, Andrey; Konuma, Mitsuharu; Jansen, Martin (2006). "An experimental proof for negative oxidation states of platinum: ESCA-measurements on barium platinides". Chemical Communications (8): 838–840. doi:10.1039/b514631c. PMID 16479284.
  115. ↑ Pt(I) and Pt(III) have been observed in bimetallic and polymetallic species; see Kauffman, George B.; Thurner, Joseph J.; Zatko, David A. (1967). "Ammonium Hexachloroplatinate(IV)". Inorganic Syntheses. Vol. 9. pp. 182–185. doi:10.1002/9780470132401.ch51. ISBN 978-0-470-13240-1.
  116. ↑ Au(0) has been observed, see Mézaille, Nicolas; Avarvari, Narcis; Maigrot, Nicole; Ricard, Louis; Mathey, François; Le Floch, Pascal; Cataldo, Laurent; Berclaz, Théo; Geoffroy, Michel (1999). "Gold(I) and Gold(0) Complexes of Phosphinine‐Based Macrocycles". Angewandte Chemie International Edition. 38 (21): 3194–3197. doi:10.1002/(SICI)1521-3773(19991102)38:21<3194::AID-ANIE3194>3.0.CO;2-O. PMID 10556900.
  117. ↑ Hg(IV) has been reported in mercury(IV) fluoride (HgF4); see Xuefang Wang; Lester Andrews; Sebastian Riedel; Martin Kaupp (2007). "Mercury Is a Transition Metal: The First Experimental Evidence for HgF4". Angew. Chem. Int. Ed. 46 (44): 8371–8375. doi:10.1002/anie.200703710. PMID 17899620. However, it could not be confirmed by later experiments; see Young, Nigel (2016-07-12). "Is mercury a transition metal?". University of Hull. Archived from the original on 2016-10-12.
  118. ↑ Tl(−5) has been observed in Na23K9Tl15.3, see Dong, Z.-C.; Corbett, J. D. (1996). "Na23K9Tl15.3: An Unusual Zintl Compound Containing Apparent Tl57−, Tl48−, Tl37−, and Tl5− Anions". Inorganic Chemistry. 35 (11): 3107–12. doi:10.1021/ic960014z. PMID 11666505.
  119. ↑ Tl(−1) has been observed in caesium thallide (CsTl); see King, R. B.; Schleyer, R. (2004). "Theory and concepts in main-group cluster chemistry". In Driess, M.; Nöth, H. (eds.). Molecular clusters of the main group elements. Wiley-VCH, Chichester. p. 19. ISBN 978-3-527-61437-0.
  120. ↑ Tl(+2) has been observed in tetrakis(hypersilyl)dithallium ([(Me3Si)Si]2Tl—Tl[Si(SiMe3)]2), see Sonja Henkel; Dr. Karl Wilhelm Klinkhammer; Dr. Wolfgang Schwarz (1994). "Tetrakis(hypersilyl)dithallium(Tl—Tl): A Divalent Thallium Compound". Angew. Chem. Int. Ed. 33 (6): 681–683. doi:10.1002/anie.199406811.
  121. ↑ Pb(−2) has been observed in BaPb, see Ferro, Riccardo (2008). Nicholas C. Norman (ed.). Intermetallic Chemistry. Elsevier. p. 505. ISBN 978-0-08-044099-6. and Todorov, Iliya; Sevov, Slavi C. (2004). "Heavy-Metal Aromatic Rings: Cyclopentadienyl Anion Analogues Sn56− and Pb56− in the Zintl Phases Na8BaPb6, Na8BaSn6, and Na8EuSn6". Inorganic Chemistry. 43 (20): 6490–94. doi:10.1021/ic000333x.
  122. ↑ Pb(0) carbonyls have been observered in reaction between lead atoms and carbon monoxide; see Ling, Jiang; Qiang, Xu (2005). "Observation of the lead carbonyls PbnCO (n=1–4): Reactions of lead atoms and small clusters with carbon monoxide in solid argon". The Journal of Chemical Physics. 122 (3): 034505. 122 (3): 34505. Bibcode:2005JChPh.122c4505J. doi:10.1063/1.1834915. ISSN 0021-9606. PMID 15740207. Also, Pb(0) has been observed in [SiII(Xant)SiII]PbFe(CO)4; see Jian Xu; Sudip Pan; Shenglai Yao; Gernot Frenking; Matthias Driess (2022). "The Heaviest Bottleable Metallylone: Synthesis of a Monatomic, Zero-Valent Lead Complex ("Plumbylone")". Angewandte Chemie International Edition. 61 (38): e202209442. doi:10.1002/anie.202209442. PMC 9545849. PMID 35848899.
  123. ↑ Pb(+1) and Pb(+3) have been observed in organolead compounds, e.g. hexamethyldiplumbane Pb2(CH3)6; for Pb(I), see Siew-Peng Chia; Hong-Wei Xi; Yongxin Li; Kok Hwa Lim; Cheuk-Wai So (2013). "A Base-Stabilized Lead(I) Dimer and an Aromatic Plumbylidenide Anion". Angew. Chem. Int. Ed. 52 (24): 6298–6301. doi:10.1002/anie.201301954. PMID 23629949.
  124. ↑ Bi(−2) and Bi(−1) occur in Zintl phases, e.g. (Ca2+)22[Bi4]4−([Bi2]4−)4[Bi3−]8; see Ponou, Siméon (2006). "Germanides, Germanide-Tungstate Double Salts and Substitution Effects in Zintl Phases". Technische Universität München. Lehrstuhl für Anorganische Chemie mit Schwerpunkt Neue Materialien. p. 68.
  125. ↑ Bi(0) state is known to exist in a N-heterocyclic carbene complex of dibismuthene; see Deka, Rajesh; Orthaber, Andreas (May 6, 2022). "Carbene chemistry of arsenic, antimony, and bismuth: origin, evolution and future prospects". Royal Society of Chemistry. 51 (22): 8540–8556. doi:10.1039/d2dt00755j. PMID 35578901. S2CID 248675805.
  126. ↑ Bi(I) has been observed in bismuth monobromide (BiBr) and bismuth monoiodide (BiI); see Godfrey, S. M.; McAuliffe, C. A.; Mackie, A. G.; Pritchard, R. G. (1998). Nicholas C. Norman (ed.). Chemistry of arsenic, antimony, and bismuth. Springer. pp. 67–84. ISBN 978-0-7514-0389-3.
  127. ↑ Bi(+2) has been observed in dibismuthines (R2Bi—BiR2), see Ashe, Arthur J. III (1990). "Thermochromic Distibines and Dibismuthines". Advances in Organometallic Chemistry. 30: 77–97. doi:10.1016/S0065-3055(08)60499-2. ISBN 9780120311309.
  128. ↑ Bi(IV) has been observed; see A. I. Aleksandrov, I. E. Makarov (1987). "Formation of Bi(II) and Bi(IV) in aqueous hydrochloric solutions of Bi(III)". Bulletin of the Academy of Sciences of the USSR, Division of Chemical Science. 36 (2): 217–220. doi:10.1007/BF00959349. S2CID 94865394.
  129. ↑ Po(V) has been observed in dioxidopolonium(1+) (PoO+
    ); see Thayer, John S. (2010). "Relativistic Effects and the Chemistry of the Heavier Main Group Elements". Relativistic Methods for Chemists. Challenges and Advances in Computational Chemistry and Physics. Vol. 10. p. 78. doi:10.1007/978-1-4020-9975-5_2. ISBN 978-1-4020-9974-8.
  130. ↑ Rn(II) has been observed in radon difluoride (RnF2); see Stein, L. (1970). "Ionic Radon Solution". Science. 168 (3929): 362–4. Bibcode:1970Sci...168..362S. doi:10.1126/science.168.3929.362. PMID 17809133. S2CID 31959268. and Kenneth S. Pitzer (1975). "Fluorides of radon and element 118". J. Chem. Soc., Chem. Commun. (18): 760b–761. doi:10.1039/C3975000760b.
  131. ↑ Rn(IV) is reported by Greenwood and Earnshaw, but is not known to exist; see Sykes, A. G. (1998). "Recent Advances in Noble-Gas Chemistry". Advances in Inorganic Chemistry. Vol. 46. Academic Press. pp. 91–93. ISBN 978-0-12-023646-6. Retrieved 22 November 2012.
  132. ↑ Rn(VI) is known in radon trioxide (RnO3); see Sykes, A. G. (1998). "Recent Advances in Noble-Gas Chemistry". Advances in Inorganic Chemistry. Vol. 46. Academic Press. pp. 91–93. ISBN 978-0-12-023646-6. Retrieved 22 November 2012.
  133. ↑ Th(-I) and U(-I) have been detected in the gas phase as octacarbonyl anions; see Chaoxian, Chi; Sudip, Pan; Jiaye, Jin; Luyan, Meng; Mingbiao, Luo; Lili, Zhao; Mingfei, Zhou; Gernot, Frenking (2019). "Octacarbonyl Ion Complexes of Actinides [An(CO)8]+/− (An=Th, U) and the Role of f Orbitals in Metal–Ligand Bonding". Chemistry (Weinheim an der Bergstrasse, Germany). 25 (50): 11772–11784. 25 (50): 11772–11784. doi:10.1002/chem.201902625. ISSN 0947-6539. PMC 6772027. PMID 31276242.
  134. ↑ Th(I) is known in thorium(I) bromide (ThBr); see Wickleder, Mathias S.; Fourest, Blandine; Dorhout, Peter K. (2006). "Thorium". In Morss, Lester R.; Edelstein, Norman M.; Fuger, Jean (eds.). The Chemistry of the Actinide and Transactinide Elements (PDF). Vol. 3 (3rd ed.). Dordrecht, the Netherlands: Springer. pp. 52–160. doi:10.1007/1-4020-3598-5_3. ISBN 978-1-4020-3555-5. Archived from the original (PDF) on 2016-03-07.
  135. ↑ Th(II) and Th(III) are observed in [ThII{η5-C5H3(SiMe3)2}3]− and [ThIII{η5-C5H3(SiMe3)2}3], see Langeslay, Ryan R.; Fieser, Megan E.; Ziller, Joseph W.; Furche, Philip; Evans, William J. (2015). "Synthesis, structure, and reactivity of crystalline molecular complexes of the {[C5H3(SiMe3)2]3Th}1− anion containing thorium in the formal +2 oxidation state". Chem. Sci. 6 (1): 517–521. doi:10.1039/C4SC03033H. PMC 5811171. PMID 29560172.
  136. ↑ Pa(II) occurs in proctactinium(II) oxide
  137. ↑ Th(-I) and U(-I) have been detected in the gas phase as octacarbonyl anions; see Chaoxian, Chi; Sudip, Pan; Jiaye, Jin; Luyan, Meng; Mingbiao, Luo; Lili, Zhao; Mingfei, Zhou; Gernot, Frenking (2019). "Octacarbonyl Ion Complexes of Actinides [An(CO)8]+/− (An=Th, U) and the Role of f Orbitals in Metal–Ligand Bonding". Chemistry (Weinheim an der Bergstrasse, Germany). 25 (50): 11772–11784. 25 (50): 11772–11784. doi:10.1002/chem.201902625. ISSN 0947-6539. PMC 6772027. PMID 31276242.
  138. ↑ U(I) has been observed in uranium monofluoride (UF) and uranium monochloride (UCl), see Sykes, A. G. (1990). "Compounds of Thorium and Uranium". Advances in Inorganic Chemistry. Vol. 34. Academic Press. pp. 87–88. ISBN 978-0-12-023634-3. Retrieved 22 March 2015. Also, U(I) has been observed in [U(η5-C5iPr5)2]−, see Barluzzi, Luciano; Giblin, Sean R.; Mansikkamäki, Akseli; Layfield, Richard A. (2022). "Identification of Oxidation State +1 in a Molecular Uranium Complex". J. Am. Chem. Soc. 144 (40): 18229–18233. doi:10.1021/jacs.2c06519. PMID 36169550. S2CID 252567088. Retrieved 13 July 2023.
  139. ↑ U(II) has been observed in [K(2.2.2-Cryptand)][(C5H4SiMe3)3U], see MacDonald, Matthew R.; Fieser, Megan E.; Bates, Jefferson E.; Ziller, Joseph W.; Furche, Filipp; Evans, William J. (2013). "Identification of the +2 Oxidation State for Uranium in a Crystalline Molecular Complex, [K(2.2.2-Cryptand)][(C5H4SiMe3)3U]". J. Am. Chem. Soc. 135 (36): 13310–13313. doi:10.1021/ja406791t. PMID 23984753.
  140. ↑ Np(II), (III) and (IV) have been observed, see Dutkiewicz, Michał S.; Apostolidis, Christos; Walter, Olaf; Arnold, Polly L (2017). "Reduction chemistry of neptunium cyclopentadienide complexes: from structure to understanding". Chem. Sci. 8 (4): 2553–2561. doi:10.1039/C7SC00034K. PMC 5431675. PMID 28553487.
  141. ↑ Pu(II) has been observed in {Pu[C5H3(SiMe3)2]3}−; see Windorff, Cory J.; Chen, Guo P; Cross, Justin N; Evans, William J.; Furche, Filipp; Gaunt, Andrew J.; Janicke, Michael T.; Kozimor, Stosh A.; Scott, Brian L. (2017). "Identification of the Formal +2 Oxidation State of Plutonium: Synthesis and Characterization ofref name="curium5" {PuII[C5H3(SiMe3)2]3}−". J. Am. Chem. Soc. 139 (11): 3970–3973. doi:10.1021/jacs.7b00706. PMID 28235179.
  142. ↑ Pu(VIII) has been observed in PuO
    4    ; see Nikonov, M. V.; Kiselev, Yu. M.; Tananaev, I. G.; Myasoedov, B. F. (March 2011). "Plutonium volatility in ozonization of alkaline solutions of Pu(VI) hydroxo complexes". Doklady Chemistry. 437 (1): 69–71. doi:10.1134/S0012500811030104. S2CID 95951175. Also see Kiselev, Yu. M.; Nikonov, M. V.; Dolzhenko, V. D.; Ermilov, A. Yu.; Tananaev, I. G.; Myasoedov, B. F. (17 January 2014). "On existence and properties of plutonium(VIII) derivatives". Radiochimica Acta. 102 (3): 227–237. doi:10.1515/ract-2014-2146. S2CID 100915090.
  143. ↑ Am(VII) has been observed in AmO−
    5    ; see Americium, Das Periodensystem der Elemente für den Schulgebrauch (The periodic table of elements for schools) chemie-master.de (in German), Retrieved 28 November 2010 and Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 1265. ISBN 978-0-08-037941-8.
  144. ↑ 144.0 144.1 144.2 Cm(V), Bk(V), and Cf(V) have been observed in BkO2+, CfO2+, CmO2(NO3)2−, BkO2(NO3)2−, and CfO2(NO3)2−; see Dau, Phuong Diem; Vasiliu, Monica; Peterson, Kirk A; Dixon, David A; Gibsoon, John K (October 2017). "Remarkably High Stability of Late Actinide Dioxide Cations: Extending Chemistry to Pentavalent Berkelium and Californium". Chemistry - A European Journal. 23 (68): 17369–17378. doi:10.1002/chem.201704193. PMID 29024093.
  145. ↑ 145.0 145.1 145.2 Kovács, Attila; Dau, Phuong D.; Marçalo, Joaquim; Gibson, John K. (2018). "Pentavalent Curium, Berkelium, and Californium in Nitrate Complexes: Extending Actinide Chemistry and Oxidation States". Inorg. Chem. 57 (15). American Chemical Society: 9453–9467. doi:10.1021/acs.inorgchem.8b01450. OSTI 1631597. PMID 30040397. S2CID 51717837.
  146. ↑ Cm(VI) has been observed in curium trioxide (CmO3) and dioxidocurium(2+) (CmO+
    2    ); see Domanov, V. P.; Lobanov, Yu. V. (October 2011). "Formation of volatile curium(VI) trioxide CmO3". Radiochemistry. 53 (5): 453–6. doi:10.1134/S1066362211050018. S2CID 98052484.
  147. ↑ Cm(VIII) has been reported to possibly occur in curium tetroxide (CmO4); see Domanov, V. P. (January 2013). "Possibility of generation of octavalent curium in the gas phase in the form of volatile tetraoxide CmO4". Radiochemistry. 55 (1): 46–51. doi:10.1134/S1066362213010098. S2CID 98076989. However, new experiments seem to indicate its nonexistence: Zaitsevskii, Andréi; Schwarz, W H Eugen (April 2014). "Structures and stability of AnO4 isomers, An = Pu, Am, and Cm: a relativistic density functional study". Physical Chemistry Chemical Physics. 2014 (16): 8997–9001. Bibcode:2014PCCP...16.8997Z. doi:10.1039/c4cp00235k. PMID 24695756.
  148. ↑ Peterson, J. R.; Hobart, D. E. (1984). "The Chemistry of Berkelium". In Emeléus, Harry Julius (ed.). Advances in inorganic chemistry and radiochemistry. Vol. 28. Academic Press. pp. 29–64. doi:10.1016/S0898-8838(08)60204-4. ISBN 978-0-12-023628-2.
  149. ↑ Peterson & Hobart 1984, p. 55.
  150. ↑ Sullivan, Jim C.; Schmidt, K. H.; Morss, L. R.; Pippin, C. G.; Williams, C. (1988). "Pulse radiolysis studies of berkelium(III): preparation and identification of berkelium(II) in aqueous perchlorate media". Inorganic Chemistry. 27 (4): 597. doi:10.1021/ic00277a005.
  151. ↑ Es(IV) is known in einsteinium(IV) fluoride (EsF4); see Kleinschmidt, P. (1994). "Thermochemistry of the actinides". Journal of Alloys and Compounds. 213–214: 169–172. doi:10.1016/0925-8388(94)90898-2.
  152. ↑ Db(V) has been observed in dubnium pentachloride (DbCl5); see H. W. Gäggeler (2007). "Gas Phase Chemistry of Superheavy Elements" (PDF). Paul Scherrer Institute. pp. 26–28. Archived from the original (PDF) on 2012-02-20.
  153. ↑ Sg(VI) has been observed in seaborgium oxide hydroxide (SgO2(OH)2); see Huebener, S.; Taut, S.; Vahle, A.; Dressler, R.; et al. (2001). "Physico-chemical characterization of seaborgium as oxide hydroxide" (PDF). Radiochim. Acta. 89 (11–12): 737–741. doi:10.1524/ract.2001.89.11-12.737. S2CID 98583998. Archived from the original (PDF) on 2014-10-25.
  154. ↑ Sg(0) has been observed in seaborgium hexacarbonyl (Sg(CO)6); see Even, J.; Yakushev, A.; Dullmann, C. E.; Haba, H.; et al. (2014). "Synthesis and detection of a seaborgium carbonyl complex". Science. 345 (6203): 1491–3. Bibcode:2014Sci...345.1491E. doi:10.1126/science.1255720. PMID 25237098. S2CID 206558746.
  155. ↑ Bh(VII) has been observed in bohrium oxychloride (BhO3Cl); see Eichler R, Düllmann C, Gäggeler HW, Eichler B, et al. "Gas chemical investigation of bohrium (Bh, element 107)" (PDF). GSI Annual Report 2000. Archived from the original (PDF) on 2008-02-28. Retrieved 2008-02-29.
  156. ↑ Hs(VIII) has been observed in hassium tetroxide (HsO4); see "Chemistry of Hassium" (PDF). Gesellschaft für Schwerionenforschung mbH. 2002. Retrieved 2007-01-31.
  157. ↑ Cn(II) has been observed in copernicium selenide (CnSe); see "Annual Report 2015: Laboratory of Radiochemistry and Environmental Chemistry" (PDF). Paul Scherrer Institute. 2015. p. 3.
Retrieved from "https://simple.wikipedia.org/w/index.php?title=Template:List_of_oxidation_states_of_the_elements&oldid=9434769"