Quantum chemical study of the structure of molybdenum pentafluoride

Experimental evidence for the molecular molybdenum fluorides MoF to MoF6: a matrix isolation and DFT investigation

“…64 However, previous DV-X a calculations yielded Mo-F ax bond lengths of 1.80 Å with Mo-F eq bond lengths of 1.89 and 1.83 Å and equatorial bond angles of 118.8 and 107.51 for a C 2v structure, and 1.83 Å and 1.84 Å, respectively, for Mo-F ax and Mo-F eq for a D 3h structure. 65 The Mulliken charges for MoF 5 are Mo This variation in bond orders is also in line with Rossi and Hoffman's prediction that axial bonds are weaker than equatorial bonds for d 1 compounds. 64 More recent, detailed CASSCF and MCQDPT2 calculations have investigated the effect of spin-orbit coupling on the stability of the Jahn-Teller distortion of MoF 5 .…”

“…64 However, previous DV-X α calculations yielded Mo–F ax bond lengths of 1.80 Å with Mo–F eq bond lengths of 1.89 and 1.83 Å and equatorial bond angles of 118.8 and 107.5° for a C 2v structure, and 1.83 Å and 1.84 Å, respectively, for Mo–F ax and Mo–F eq for a D 3h structure. 65…”

“…For AgF, the argon (497.5 cm À1 ) and neon (497.7 cm À1 ) matrix values were redshifted from the gas phase value of 508.3 cm À1 , indicating a weaker interaction, with calculated binding energies of 21.1 kJ mol À1 (Ar-AgF) and 3.7 kJ mol À1 (Ne-ArF). For CuF the argon matrix bands at 615.9 and 610.6 cm À1 for 63 CuF and 65 CuF were slightly blueshifted compared to the gas phase value of 614.8 cm À1 for 63 CuF. The binding energies were calculated to be 11.2 kJ mol À1 for Ne-CuF and 43.9 kJ mol À1 for Ar-CuF.…”

“…64 However, previous DV-X a calculations yielded Mo-F ax bond lengths of 1.80 Å with Mo-F eq bond lengths of 1.89 and 1.83 Å and equatorial bond angles of 118.8 and 107.51 for a C 2v structure, and 1.83 Å and 1.84 Å, respectively, for Mo-F ax and Mo-F eq for a D 3h structure. 65 The Mulliken charges for MoF 5 are Mo 1.691 and F ax À0.379 , F ax À0.379 , F eq À0.318 F eq À0.315 and F eq À0.300 . The Mulliken spin densities are 0.870 for Mo and o 0.1 for F. The DDEC6 NACs are Mo 3.920 and F ax À0.871 , F ax À0.871 , F eq À0.734 F eq À0.…”

Influence of the temperature and phase state of K,Ca/NO3 and K,Mg/NO3 binary systems on the vibrational anharmonicity and orientational mobility of the nitrate ion

“…The asymmetric distortion of the low frequency wing of the ν 1 (A 1 ′ ) band, the complex structure of ν 2 (A 2 ′′ ) (these bands correspond to fully symmetric and nondegenerate deformation vibrations of NO 3 − out of the plane), and the splitting of the ν 4 (E) profile are indicative of the presence of two sets of nitrate ions in the heterophase glass -filler particles in the bulk and localized in the surface region. This kind of high sensitivity of the vibrational spectrum of a molecular ion to changes in the cluster geometry and to the surroundings of a molecular ion outside the sphere is well known [11]. The mobility of the NO 3 − anions localized in the surface region at particles of the solid filler NO 3 − may differ from the mobility of bulk nitrate ions located in the composition of the IAC.…”