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

Copper(I), silver(I) and gold(I) complexes with the ligand 1-(diphenyp hosphino)-2-(2-pyridyl)ethane (ppye) of general formula M(ppye)(2)PF6 have been prepared and characterized by means of IR and multinuclear ( H-1,C-13 and np) NMR spectroscopy The copper(I) and silver(I) complexe s are bis(chelate) with a tetrahedral geometry around the metal atom. On the contrary, the gold(I) derivative exhibits a digonal structure w ith monodentate P-bound ppye ligands co-ordinated to the metal centre. The complex [Au(ppye-P)(2)]PF6 has been characterized in the solid st ate by X-ray diffraction analysis. Crystal data: triclinic, space grou p P ($) over bar 1, a=9.972(1), b=10.299(2), c=10.521(2) Angstrom, alp ha=69.90(2), beta=66.03(1), gamma=78.51(1)degrees, Z=1, R=0.039. The g old atom. which lies on a symmetry centre, is linearly co-ordinated by the P atoms of ppye (P-Au-P, 180 degrees). Variable-temperature NMR s tudies 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 t he cations [M(ppye-P,N)(2)](+) and [Au(ppye-P)(2)](+) with ppye have b een investigated.