Silver(I) complexes with the mixed P/O donor ligand Ph 2P(CH 2) 2O(CH 2) 2O(CH 2) 2PPh 2 (L 1) and the crystal structures of [Ag(L 1)](CF 3SO 3), [Ag 2(L 1) 3](CF 3SO 3) 2 and [Ag(L 1)(NO 3)

Abstract

The Ag(I) salts AgY (Y=ClO 4, CF 3SO 3, NO 3, Cl or I) react with one molar equivalent of the diphosphinodiether ligand Ph 2P(CH 2) 2O(CH 2) 2O(CH 2) 2PPh 2 (L 1) to give 1:1 species of stoichiometry Ag(L 1)Y. The structures of these species have been investigated in solution by 31P NMR spectroscopy and for [Ag(L 1)](ClO 4), [Ag(L 1)](CF 3SO 3) and [Ag(L 1)(NO 3)] in the solid state by single crystal X-ray diffraction. In particular, the 107Ag–P and 109Ag–P coupling constants provide a convenient method for identifying the solution speciation, especially for the occurrence of anion coordination in the nitrate and halide complexes. The conclusions from the NMR spectroscopic studies are also consistent with the solid state structures. Addition of a further equivalent of L 1 to [Ag(L 1)](CF 3SO 3) results in a very significant drop in the Ag–P coupling constants, indicative of higher P-coordination at Ag(I), now involving three P-donor atoms. This conclusion is also borne out by a crystallographic study on [Ag 2(L 1) 3](CF 3SO 3) 2 which shows a dinuclear cation with one chelating L 1 and one bridging L 1 ligand coordinated to each metal centre, giving a distorted trigonal planar geometry.