Copper(I), silver(I) and gold(I) complexes with the hybrid ligand 1-(diphenylphosphino)-2-(2-pyridyl)ethane (ppye). Variable-temperature nuclear magnetic resonance investigations and the crystal structure of [Au(ppye-P)2]PF6

Abstract

Copper(I), silver(I) and gold(I) complexes with the ligand 1-(diphenylphosphino)-2-(2-pyridyl)ethane (ppye) of general formula M(ppye)2PF6 have been prepared and characterized by means of IR and multinuclear (1H, 13C and 31P) NMR spectroscopy. The copper(I) and silver(I) complexes are bis(chelate) with a tetrahedral geometry around the metal atom. On the contrary, the gold(I) derivative exhibits a digonal structure with monodentate P-bound ppye ligands co-ordinated to the metal centre. The complex [Au(ppye-P)2]PF6 has been characterized in the solid state by X-ray diffraction analysis. Crystal data: triclinic, space group P, a= 9.972(1), b= 10.299(2), c= 10.521(2)A, α= 69.90(2), β= 66.03(1), γ= 78.51(1)°, Z= 1, R= 0.039. The gold atom, which lies on a symmetry centre, is linearly co-ordinated by the P atoms of ppye (P–Au–P, 180°). Variable-temperature NMR studies show that the [M(ppye-P,N)2]+ species rearrange in solution by inversion at the tetrahedral metal centre. Furthermore, all three ppye derivatives undergo ligand-exchange processes. The reactions of the cations [M(ppye-P,N)2]+ and [Au(ppye-P)2]+ with ppye have been investigated.