Unstable intermediates. Part CLIII. Electron spin resonance spectra and structure of dichlorophosphoranyl radicals

Abstract

A range of dichlorophosphoranyl radicals [(RO)P(O)Cl₂][graphic omitted] have been prepared by exposure of the neutral molecules, (RO)P(O)Cl₂, to ⁶⁰Co γ-rays at 77 K [R = Me, Et, Ph, C₁₀H₇(α-naphthyl), MeOCH₂CH₂, or ClCH₂CH₂]. Well resolved e.s.r. spectra obtained from [(MeO)POCl₂][graphic omitted] and [(EtO)POCl₂][graphic omitted] have enabled the components of the ³¹P and ^35,37Cl hyperfine-coupling tensors to be derived. The results show that both tensors are nearly axial, but their principal axes are at right angles to each other. The two chlorine ligands must be nearly coaxial with the phosphorus atom and they share ca. 50% of the total spin density, the remainder being confined to 3s and 3p orbitals on phosphorus.