Some calculated properties of phenylphosphinidene (C 6H 5P)

Abstract

Ab initio molecular orbital (MP2/6-311G(d,p) and CASPT2/ANO) and density functionl theory (DFT/IGLO-III) calculations have been applied to determine some basic properties of phenyl phosphinidenee (C 6H 5P). Geometrics, harmonic vibrational wavenumbers, singlet-triplet energy gaps, heats of formation and hyperfine splitting constants have been calculated. Phenylphosphinidene has a triplet 3A 2 ground state lying 22±3 kcal/mol below the closed-shell singlet 1A 1 state and some calculated properties are: heat of formation at 0 K ΔH 0 f,0 = 68 ± 5 kcal/mol, vertical ionization energy IE v = 10.6 ± 0.3 eV, electron affinity EA a = 0.89±03 eV, proton affinity PA = 140±5 kcal/mol and isotropic hyperfine splitting constant a( 31 P) = 66 ± 3 G . The open-shell singlet 1A 2 state is a low-lying state having comparable energy with the 1A 1. The properties of C 6H 5P are similar to those of methylphosphinidene (CH 3P). The singlet-triplet gap ( 1A′– 3A 2) in CH 3P amounts to 26 ± 3 kcal/mol. Relative to the CH 3P, the phneyl group has a small effect on the singlet state but seems to destabilize the triplet state and thereby reduce the singlet-triplet gap.