Platinum-Assisted Addition of Carbonyl-Stabilized Phosphorus Ylides to Pentafluorobenzonitrile and Acetonitrile To Give Platinum(II) Complexes Containing Iminophosphorane and/or N-Bonded β-Imino Phosphorus Ylide Ligands. Crystal and Molecular Structures of trans-[PtCl2{E-NHC(C6F5)C(PPh3)C(O)Me}2] and trans-[PtCl2{E-N(PPh3)C(C6F5)CHCO2Et}{E-NHC(C6F5)C(PPh3)CO2Et}]

PtCl(2) reacts with C(6)F(5)CN to give trans-[PtCl(2)(NCC(6)F(5))(2)] (1) which, in turn, reacts with carbonyl-stabilized phosphorus ylides Ph(3)P=CHR [R = C(O)Me, CO(2)Et] to give trans-[PtCl(2){NH=C(C(6)F(5))C(=PPh(3))CO(2)Et}{NCC(6)F(5)}] (2a), trans-[PtCl(2){NH=C(C(6)F(5))C(=PPh(3))CO(2)Et}(2)] (3a), trans-[PtCl(2){E-NH=C(C(6)F(5))C(=PPh(3))C(O)Me}(2)] (3b) or trans-[PtCl(2){E-N(=PPh(3))C(C(6)F(5))=CHCO(2)Et}{E-NH=C(C(6)F(5))C(=PPh(3))CO(2)Et}] (4), depending on the reaction conditions. Similarly, Ph(3)P=CHCO(2)Me reacts with trans-[PtCl(2)(NCMe)(2)] to give trans-[PtCl(2){NH=CMeC(=PPh(3))CO(2)Me}(NCMe)] (2b). Complex 3b.CH(2)Cl(2) crystallizes in the triclinic system, space group P, with a = 7.596(2) Å, b = 12.694(3) Å, c = 16.962(3) Å, alpha = 104.28(3) degrees, beta = 102.73(3) degrees, gamma = 104.43(3) degrees, V = 1464.2(6) Å(3), and Z = 1. The structure was refined to values of R1 = 0.0411 and wR2 = 0.1172 [I >2sigma(I)] and shows two chloro and two N-bonded beta-imino phosphorus ylide ligands in a trans geometry. Complex 4 crystallizes in the monoclinic system, space group P2(1)/c, with a = 16.400(8) Å, b = 14.354(7) Å, c = 23.221(12) Å, alpha = 90(3) degrees, beta = 92.42(2) degrees, gamma = 90 degrees, V = 5462(5) Å(3), and Z = 4. The structure was refined to values of R1 = 0.0246 and wR2 = 0.0557 [I >2sigma(I)]. This complex has also a trans-geometry and shows that while the attack of the ylide on one of the nitrile ligands produces a beta-imino-phosphorus ylide ligand the addition on the second nitrile leads to an iminophosphorane ligand.