An iodide/anion exchange route to benzimidazolylidene silver complexes from benzimidazolium iodide: Crystal structures of N, N′-dibutylbenzimidazolylidene silver chloride, bromide, cyanide and nitrate

Abstract

Syntheses of N, N′-dibutylbenzimidazolylidene silver complexes having chloride, nitrate or cyanide as an anion part through an iodide/anion exchange from N, N′-dibutylbenzimidazolium iodide are described, representing a practical route to benzimidazolylidene silver complexes from readily accessible benzimidazolium iodide. The crystal structures of N, N′-dibutylbenzimidazolylidene silver chloride, bromide, cyanide and nitrate have been determined, showing a close ligand-unsupported Ag–Ag interaction in [(NHC) 2]Ag +[AgX 2] − and a “T” shape geometry about the silver(I) cation in complexes of chloride, bromide and cyanide, but a nearly linear shape in the bis( N, N′-dibutylbenzimidazolylidene) silver complex [ ( NHC ) 2 Ag ] + NO 3 - with non-coordinating nitrate anion.