Electronic Structure and Spectroscopic Properties of Group-7 Tri-Oxo-Halides MO3X (M = Mn-Bh, X = F-Ts)

The 24 trioxide halide molecules MO₃X of the manganese group (M = Mn-Bh; X = F-Ts), which are iso-valence-electronic with the famous MnO_4^- ion, have been quantum-chemically investigated by quasi-relativistic density-functional and ab initio correlated approaches. Geometric and electronic structures, valence and oxidation numbers, vibrational and electronic spectral properties, energetic stabilities of the monomers in the gas phase, and the decay mode of MnO₃F have been investigated. The light Mn-3d species are most strongly electron-correlated, indicating that the concept of a closed-shell Lewis-type single-configurational structure [Mn⁺⁷(d⁰) O^-2(p⁶)₃ F^-(p⁶)] reaches its limits. The concept of real-valued spin orbitals φ(r)·α and φ(r)·β breaks down for the heavy Bh-6d, At-6p and Ts-7p elements because of the dominating spin-orbit coupling. The vigorous decomposition of MnO₃F at ambient conditions starts by the autocatalyzed release of n O₂ and the formation of Mn_mO_3m-2nF_m clusters, triggered by the electron-depleted "oxylic" character of the oxide ligands in MnO₃X.

Permanganyl Fluoride: A Brief History of the Molecule MnO3 F and of Those Who Cared For It

Permanganyl fluoride's existence at the stability threshold in the series of oxides and oxide fluorides of the late 3d transition metals is reflected by its experimentally challenging properties and by the difficulties posed in the theoretical description of its bonding characteristics. The history of this molecule is reviewed from early qualitative observations and the growing scattered information on its chemical and physical properties to the accurate determination and interpretation of its molecular structure and spectral features. The still problematic theoretical models for MnO4 - and MnO3 F are briefly presented in the broader context of the chemistry of elements in high oxidation states. Short biographies of the scientists engaged in these studies are offered. Related technetium and rhenium compounds are briefly considered for comparison.

Topochemical Oxidation of Perovskite KCoF3 to a K2PtCl6 Structure-Type Oxyfluoride

Oxyfluoride, K2CoOF4 with K2PtCl6 structure, has been stabilized from a perovskite-based KCoF3 complex by a simple oxidative anion insertion topochemical reaction. Similar structural transformations have been observed for Ni- and Mn-containing systems. The generation of such unusual compounds, by soft chemical methods, strengthens the efforts toward materials discovery.

The OsO(3)F(+) and mu-F(OsO(3)F)(2)(+) cations: their syntheses and study by Raman and (19)F NMR spectroscopy and electron structure calculations and X-ray crystal structures of [OsO(3)F][PnF(6)] (Pn = As, Sb), [OsO(3)F][HF](2)[AsF(6)], [OsO(3)F][HF][SbF(6)], and [OsO(3)F][Sb(3)F(16)]

The fluoride ion donor properties of OsO(3)F(2) have been investigated. The salts [OsO(3)F][AsF(6)], [OsO(3)F][HF](2)[AsF(6)], mu-F(OsO(3)F)(2)[AsF(6)], [OsO(3)F][HF](2)[SbF(6)], and [OsO(3)F][HF][SbF(6)] have been prepared by reaction of OsO(3)F(2) with AsF(5) and SbF(5) in HF solvent and have been characterized in the solid state by Raman spectroscopy. The single-crystal X-ray diffraction studies of [OsO(3)F][AsF(6)] (P2(1)/n, a = 7.0001(11) A, c = 8.8629(13) A, beta = 92.270(7) degrees, Z = 4, and R(1) = 0.0401 at -126 degrees C), [OsO(3)F][SbF(6)] (P2(1)/c, a = 5.4772(14) A, b = 10.115(3) A, c = 12.234(3) A, beta = 99.321(5) degrees, Z = 4, and R(1) = 0.0325 at -173 degrees C), [OsO(3)F][HF](2)[AsF(6)] (P2(1)/n, a = 5.1491(9) A, b = 8.129(2) A, c = 19.636(7) A, beta = 95.099(7) degrees, Z = 4, and R(1) = 0.0348 at -117 degrees C), and [OsO(3)F][HF][SbF(6)] (Pc, a = 5.244(4) A, b = 9.646(6) A, c = 15.269(10) A, beta = 97.154(13) degrees, Z = 4, and R(1) = 0.0558 at -133 degrees C) have shown that the OsO(3)F(+) cations exhibit strong contacts to the anions and HF solvent molecules giving rise to cyclic, dimeric structures in which the osmium atoms have coordination numbers of 6. The reaction of OsO(3)F(2) with neat SbF(5) yielded [OsO(3)F][Sb(3)F(16)], which has been characterized by (19)F NMR spectroscopy in SbF(5) and SO(2)ClF solvents and by Raman spectroscopy and single-crystal X-ray diffraction in the solid state (P4(1)m, a = 10.076(6) A, c = 7.585(8) A, Z = 2, and R(1) = 0.0858 at -113 degrees C). The weak fluoride ion basicity of the Sb(3)F(16)(-) anion resulted in an OsO(3)F(+) cation (C(3)(v) point symmetry) that is well isolated from the anion and in which the osmium is four-coordinate. The geometrical parameters and vibrational frequencies of OsO(3)F(+), ReO(3)F, mu-F(OsO(3)F)(2)(+), (FO(3)Os--FPnF(5))(2), and (FO(3)Os--(HF)(2)--FPnF(5))(2) (Pn = As, Sb) have been calculated using density functional theory methods.