Preparation and structure of certain phosphorus-centred radical cations. An electron spin resonance study

Abstract

Exposure of dilute solutions of various trivalent phosphorus derivatives, PL₃, in fluorotri-chloromethane to ⁶⁰Co γ-rays at 77 K gave the corresponding cations, [·PL₃]⁺, characterised by their e.s.r. spectra. The spectra establish that the SOMO for these cations is considerably localised on phosphorus, which contributes extensive atomic 3s and 3p character. The results confirm and extend previous studies using sulphuric acid matrices. The tendency for these cations to react with corresponding neutral molecules to give σ^* dimer-cations [L₃P[graphic omitted]PL₃]⁺ is also confirmed.

The structures of these species are discussed and compared with those of related radicals.