Copper(I), silver(I) and gold(I) complexes of N-heterocyclic carbene-phosphinidene

N-heterocyclic carbene stabilized phosphinidene IMes.PPh has been used as a bridging ligand to isolate a group of closely related molecules involving all three coinage metal ions. The bis-copper(I) chloride, bis-silver(I) chloride and bis-copper(I) bromide adducts of IMes.PPh crystallize as halide ion bridged octanuclear molecules while the [IMes.PPh](AuCl)(2) adduct remains monomeric. These molecules feature long P-C(carbene) bonds in the range 1.822(3)-1.843(4) angstrom, near the typical P-C single bond length region.