Ab initio localized orbital calculations of the bonding in phosphines and phosphine complexes

Abstract

Localized orbital calculations of the bonding in the phosphines PH₃, PMe₃, PF₃ and PCl₃ and the phosphine complexes PH₃O, PF₃O, PMe₃O, PCl₃O, PH₃BH₃, PF₃BH₃ and PF₃S are described using the unitary transform of Boys. A description of the bonding in terms of lone pairs and bond pairs is obtained and the nature of d orbital participation in these molecules is shown. In the phosphines (PX₃), 3d functions participate only in the P—X bond orbitals, whilst in the oxides the three equivalent P—O bonding orbitals involve the phosphorus 3d functions. The boranes have a single P—B bond involving the valence p orbitals of the two atoms.