Two- and four-coordinated gold(I) complexes with aryldithiocarboxylates and triphenylphosphine. X-ray diffraction crystal structure of the [Au(S2CPh)PPh3], [Au(S2CPh)(PPh3)2] and [Au0.56Cu0.44(S2C-p-tolyl)(PPh3)2] complexes; NMR investigations of [Au(S2CAr)(PPh3)n] (n=1, 2) compounds in solution