TETRAFLUOROETHYL COMPLEXES DERIVED FROM INSERTION OF THE TETRAFLUOROETHYLENE LIGAND INTO AN IRIDIUM-HYDRIDE BOND

The reaction of IrH(CO)(PPh3)3 with tetrafluoroethylene gives the hydride olefin complex IrH-(C2F4)(CO)(PPh3)2. Further reactions of IrH(C2F4)(CO)(PPh3)2 with a coordinating ligand L (L = C2F4>CO, C2H4) result in the insertion of the coordinated olefin into the iridium-hydrogen bond and formation of tetrafluoroethyl complexes, Ir(CF2CF2H)(L)(CO)(PPh3)2. Thermal displacement of the ethylene ligand in Ir(CF2CF2H)(C2H4)(CO)(PPh3)2 gives the four-coordinate complex Ir(CF2CF2H)(CO)(PPh3)2. The X-ray crystal structure of the dicarbonyl complex Ir(CF2CF2H)(CO)2(PPh3)2 is described. Ir(CF2CF2H)(CO)2(PPh3)2 crystallizes in the triclinic space group.PI with α — 9.868 (5) Â, b — 11.5727 (5) Â, c — 17.083 (9) Â, <x=103.9 (4)°, β = 94.14 (4)°, y = 113.09 (3)°, and Z = 2 with d(calcd) = 1.699 g cm-3 for a molecular weight of 873.83. The structure was refined to give R = 0.0400 and Rv = 0.0407, and in contrast to the geometry displayed in solution, which has trans triphenylphosphines, has a eis arrangement of triphenylphosphine ligands. The Ir-CF2CF2H bond distance is 2.145 (8) Â. © 1990, American Chemical Society. All rights reserved.