Synthesis and Structure of a CuI3S Cluster Unsupported by Other Bridging Ligands

Abstract

The facile synthesis of a {LCuI}3(μ3-S) cluster supported by monodentate N-heterocyclic carbene ligands has been accomplished through an approach in which two-coordinate (NHC)Cu+ centers are installed sequentially on a sulfido ligand. The reaction between (IPr)CuCl (IPr = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) and S(SiMe3)2 yields (IPr)Cu(SSiMe3) (2). Treatment of 2 with [(IPr)Cu(NCMe)][BF4] produces the dicopper cluster [{(IPr)Cu}2(μ-SSiMe3)][BF4] (3[BF4]), which undergoes subsequent reaction with (IPr)CuF to afford [{(IPr)Cu}3(μ3-S)][BF4] (1[BF4]) in high yield. The X-ray crystal structure of 1[BF4] establishes it as a rare example of a CuIn(μn-S)Lm cluster, and the first that is not also supported by other bridging ligands.