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Quantum‐Mechanical ab initio Investigation of the Transition‐Metal Compounds OsO 4 , OsO 3 F 2 , OsO 2 F 4 , OsOF 6 , and OsF 8
Author(s) -
Veldkamp Achim,
Frenking Gernot
Publication year - 1993
Publication title -
chemische berichte
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 0009-2940
DOI - 10.1002/cber.19931260609
Subject(s) - chemistry , ab initio , bond length , ab initio quantum chemistry methods , ionic bonding , molecular geometry , hypersurface , symmetry (geometry) , atomic physics , chemical bond , crystallography , molecule , crystal structure , physics , geometry , ion , mathematical analysis , mathematics , organic chemistry
The equilibrium geometries of OsO 4 , OsO 3 F 2 , OsO 2 F 4 and OsF 8 are theoretically predicted by using quantum‐mechanical ab initio methods at the Hartree‐Fock and MP2 level of theory employing quasi‐relativistic pseudopotentials for Os and 3‐21G and 6‐31G(d) basis sets for O and F. A comparison of the calculated geometries and vibrational frequencies with available experimental results shows a good agreement. The energy minimum structure for OsO 4 has T d symmetry, for OsO 3 F 2 it has D 3 h symmetry, for OsO 2 F 4 C 2v symmetry with cis 1‐coordinated oxygen atoms, and for OsF 8 a D 2d symmetry with two different Os – F bond lengths is predicted. OsOF 6 is not a minimum on the potential energy hypersurface. The calculation of the thermodynamic stabilities indicates that the Os – F bond in OsF 8 is clearly weaker than in OsO 3 F 2 , OsO 2 F 4 and in OsF 6 . It will be very difficult to observe OsF 8 experimentally. The analysis of the electronic structure shows that the Os – O bond is partly covalent, while the Os – F bonds are mainly ionic.