Coinage metal complexes of selenoureas derived from N-heterocyclic carbenes

Abstract

We describe the synthesis and characterisation of a series of new copper and silver complexes with selenourea ligands derived from common and readily-prepared N-heterocyclic carbenes (NHCs). The copper complexes behave somewhat predictably, typically leading to [CuCl(L)] complexes (with two exceptions). The silver complexes display a diverse range of structural motifs, including [AgCl(μ-L)]₂, [AgCl(L)₂], [Ag(L)₂]⁺, [Ag(L)₃]⁺, and [(Ag(L)₂)₂(μ-L)]²⁺ species. All new complexes are characterised by multinuclear NMR spectroscopy, and several examples are characterised by X-ray crystallography. This study demonstrates the diversity of coordination behaviour that these selenourea ligands can engage in.