The radical cation of trimethylamine–boron hydride: An EPR study

Abstract

Exposure of dilute solutions of trimethylamine–boron hydride (Me₃N–BH₃) in freon (CFCl₃) at 77 K to ionizing radiation gave a radical cation whose EPR spectrum was that expected for the parent radical cation. This resembled those obtained for the BH₄ radical previously studied, having a nearly isotropic hyperfine coupling to boron, and a large coupling to two equivalent protons. The possibility that this might be a σ¹-radical the SOMO being the N–B σ-bond is dismissed: the favoured structure places the hole on two hydrogens and on boron only.