A tropylium annulated N-heterocyclic carbene

Chem Commun (Camb). 2020 Aug 14;56(63):9020-9023. doi: 10.1039/d0cc04482b. Epub 2020 Jul 8.

Abstract

Derivatives of the cationic tropylium annulated imidazolylidene ITrop+ are obtained by hydride abstraction from related cycloheptatriene compounds. Spectroscopic, structural and theoretical data indicate that, as a cationic relative of benzimidazolylidenes, ITrop+ has highly reduced σ-donor and strong π-acceptor character.