Transient resonance Raman and density functional theory investigation of 4-methoxyphenylnitrenium and 4-ethoxyphenylnitrenium ions

Abstract

This paper presents a transient resonance Raman and density functional theory study of 4-methoxyphenylnitrenium and 4-ethoxyphenylnitrenium ions in a largely aqueous environment. The transient Raman bands observed in conjunction with the (U)BPW91/cc-PVDZ calculation results indicates these nitrenium ions are singlet state species. Both the 4-methoxyphenylnitrenium and the 4-ethoxyphenylnitrenium ions have significant iminocyclohexadienyl character to a degree very similar to that previously found for the 2-fluorenylnitrenium ion. The 4-methoxyphenylnitrenium and the 4-ethoxyphenylnitrenium ions also have significant oxocarbocation character and this influences both their properties and chemical reactivity. We compare the properties of the 4-methoxyphenylnitrenium and the 4-ethoxyphenylnitrenium ions to those previously found for other arylnitrenium ions.