Unstable intermediates. Part 112.—Radiation damage in plumbous acetate: electron spin resonance spectrum of a PbMe2+ adduct

Abstract

Exposure of plumbous acetate to ⁶⁰Co γ-rays at 77 K gave a centre having A_‖(²⁰⁷Pb)= 1928 G, A_⊥(²⁰⁷Pb)= 1700 G, A_‖(Me) [graphic omitted] 24 G, A_⊥(Me)=+20 G, g_‖= 1.953 and g_⊥= 1.988. This corresponds to a spin-density of about 60% on lead in an orbital having considerable 6p content. The form of the proton coupling strongly suggests that the coupling is positive and hence the methyl group is probably pyramidal with the unpaired electron in the Pb—C σ^* orbital. Radicals of this class seem to be unprecedented in e.s.r. studies.