Phenylcyanamidocopper(I) and silver(I) complexes: Synthetic and structuralstudies

Phenylcyanamidocopper(I) and silver(I) complexes of the type, [{M(PPh3)(2)L }(2)] (M = Cu, L = 4-NO(2)pcyd or 4-Me(2)Npcyd; M = Ag, L = 4-Me(2)Npcyd), [Cu(PPh3)(3)L] (L = pcyd or 4-NO2-pcyd), [Ag(PPh3)3L] (L = pcyd, 2-Clpcyd, 4-Clpcyd, 4-Brpcyd, 4-MeOpcyd, 4-NO(2)pcyd or 4-Me(2)Npcyd), [Ag(Me(2)phen) (2-Clpcyd)] (Me(2)phen = 2,9-dimethyl-1,10-phenanthroline) and [Ag(dppm)(4- Brpcyd)] (dppm = bis( diphenyl-phosphino)methane) have been synthesised and characterised and the crystal structures of four of the complexes determin ed. For both [{Cu(PPh3)(2)(4-Me(2)Npcyd)}(2)]. CH2Cl2 and [(Ag(PPh3)(2)(4-M e(2)Npcyd)}(2)], the cyanamide ligands bridge the metal atoms in a mu-1,3-f ashion through the cyano and amido nitrogens. Each metal atom has a distort ed tetrahedral geometry, being bound to two triphenylphosphine phosphorus a toms and two nitrogen atoms from 4-Me(2)Npcyd ligands to give a 'P2N2' coor dination sphere. In the case of the Cu complex the dimer is centrosymmetric but for the Ag complex the metal atoms are not equivalent. The complexes, [Ag(PPh3)(3)(4-Brpcyd)] and [Ag(PPh3)(3)(4-Me-Opcyd)], are discrete monomer s, in which each of the Ag atoms adopts a distorted tetrahedral geometry, b eing bound to three triphenylphosphine phosphorus atoms and one phenylcyana mide ligand binding in a terminal fashion through the cyano nitrogen.