PSEUDOELEMENT COMPOUNDS - XII - ON THE CHARACTERIZATION OF 1,1,2,3,3-PENTACYANOPROPENIDE IN UNIDENTATE AND BIDENTATE FUNCTION - SYNTHESES OF COMPLEXES OF THE TYPE [MX(PPH3)(N)] (M = CU-I, AG-I X = NCC(C(CN)(2))(2) N = 2,3)

1,1,2,3,3-Pentacyanopropenide is characterized as unidentate and biden tate ligand. For that reason compounds of the types [MX(PPh3)(3)] (6) and [MX(PPh3)(2)](2) (8) (hl = Cu-I, Ag-I) are synthesized. In the com plexes 6 the ionic ligand is coordinated unidentately through an end-o n nitrile group of a C(CN)(2) unit and in the dimeric complexes 8 bide ntately bridging through the N atoms of a C(CN)(2) moiety too. The com pounds are characterized by C-13 NMR, P-31 NMR and LR spectroscopy. Th e crystal structure of [AgX(PPh3)(3)] is presented and the structural parameters of the anion in this complex and in [CuX(PPh3)(2)](2) [x = NCC(C(CN)(2))(2)] are compared.