Evaluating the thermal behaviour of benzimidazolylidene sources for thin-film applications

Abstract

We show that the N-heterocyclic carbene precursor employed has a significant influence on the purity of the resulting films prepared by vapour-phase deposition. 1,3-Diisopropylbenzimidazolylidene is stable up to 363 K, before undergoing thermal decomposition to 1,2-diisopropylbenzimidazole as the major product. Various minor products arising from wing-tip loss are also observed. Kinetic and thermochemical analyses indicate that this reaction is second-order with respect to the carbene and proceeds through a transient tetraazafulvalene.