Oxidation State 10 Exists

Abstract

In a recent paper, Wang et al. found an iridium-containing compound with a formal oxidation state of 9. This is the highest oxidation state ever found in a stable compound. To learn if this is the highest chemical oxidation state possible, Kohn-Sham density functional theory was used to study various compounds, including PdO4 (2+) , PtO4 (2+) , PtO3 F2 (2+) , PtO4 OH(+) , PtO5 , and PtO4 SH(+) , in which the metal has an oxidation state of 10. It was found that PtO4 (2+) has a metastable state that is kinetically stable with a barrier height for decomposition of 31 kcal mol(-1) and a calculated lifetime of 0.9 years. All other compounds studied would readily decompose to lower oxidation states.

Über Oxidationszahl‐Obergrenzen in der Chemie

“…[7] However, our attempts to synthesize Ir +9 -compounds in the bulk have failed so far, indicating that OS ≈ +9±1 may represent the borderland for chemical stability under ambient conditions, and for the stability of single molecules under exotic conditions. Pyykkö [7c] has noted that often "prediction precedes production", and a previous paper [8] predicted OS = +10 for species [Pt +10 O4] 2+ ( Fig. 1-left) which was highlighted in various media.…”

“…S1 in the Supporting Information SI), had been obtained applying singlet spin-restricted density-functional approximations (DFAs). [8] Applying here higher-quality spin-unrestricted DFAs and multiconfiguration wave-function (WF) approaches (Tables S1 and S2) (Table S3). The mono-cations are observable as building blocks of some crystalline materials.…”

Beyond Oxides: Nitride as a Ligand in a Neutral IrIXNO3 Molecule Bearing a Transition Metal at High Oxidation State

“…Note that the barrier computed here for IrNO 3 is larger than that of 122.2 kJ mol À1 determined previously for [PtO 4 ] 2 + (corresponding to unimolecular lifetimee qual to 0.86 years). [18] We concludet hat the IrNO 3 E structure, thanks to high energy barriers, is kinetically stable to decomposition.…”

“…shift evidencef or the existence as hort-lived [IrO 4 ] + originating from radioactive decay. [17] In 2016, Yu [18] Although these important resultsc hange the stereotypical thinking about the formal oxidation states,i ts hould be noted that the molecules at hand correspond to cationic and not neutral species. Therefore, one cannot isolate these systems in large concentration typical of ag enuine extended phase.…”

Valence Interconversion of Octahedral Nickel(II/III/IV) Centers

“…From these observations,a nd together with the simulated EPR spectrum for [1] 3+ (Supporting Information, Figure S5), [1] 2+ ,[ 1] 3+ ,a nd [1] 4+ were determined to contain d 8 Ni II (S = 1), low-spin d 7 Ni III (S = 1/2), and low-spin d 6 Ni IV (S = 0) centers,respectively. [33] Thelow-spin d 6 Ni IV center in [1] 4+ was also supported by 1 HNMR spectroscopy,w hich gave as ingle set of sharp signals (Supporting Information, Figure S6). [33] Thes tructures of [1](NO 3 ) 2 ,[ 1](NO 3 ) 3 ,a nd [1](NO 3 ) 4 were established by single-crystal X-ray crystallography, which revealed the presence of complex cations and nitrate anions in ratios of 1:2, 1:3, and 1:4, respectively.…”