CARBON-FLUORINE AND CARBON-HYDROGEN BOND ACTIVATION AND CARBON-CARBONBOND FORMATION IN ETA(5)-PENTAMETHYLCYCLOPENTADIENYL-RHODIUM AND ETA(5)-PENTAMETHYLCYCLOPENTADIENYL-IRIDIUM PHOSPHINE COMPLEXES - CRYSTAL-STRUCTURES OF 5)ME(5))CL((C6F5)(2)PCH2CH2P-(C6F5)(2))](BF4-)-B-+ (M=RH OR IR)

The reaction between [{M(eta(5)-C(5)Me(5))Cl(mu-Cl)}(2)] (M = Ph or Ir ) and (C6F5)(2)PCH2CH2P(C6F5)(2) (dfppe) in refluxing benzene yielded the cationic species {eta(5)-C(5)Me(3)[CH2C6F4P(C6F5)CH2](2)-1,3}Cl]() in which two C-F and two C-H bonds have been cleaved and two C-C bon ds formed; HF is also produced. The complexes [M(eta(5)-C(5)Me(5))Cl(d fppe)](BF4-)-B-+ (M = Ph or Ir), which have not undergone C-F bond act ivation, were formed by treatment of [{M(eta(5)-C(5)Me(5))Cl(mu-Cl)}(2 )] with NH4BF4 and dfppe, and have been structurally characterized by X-ray crystallography. Activation of the C-F bonds in these complexes is induced by thermolysis in refluxing ethanol. The reaction between [ {M(eta(5)-C(5)Me(5))Cl(mu-Cl)}(2)] (M = Rh or Ir) and dfppe in refluxi ng ethanol yielded a mixture of the cations [M(eta(5)-C(5)Me(5))Cl(dfp pe)](+), (3)[CH2C6F4P(C6F5)CH2C6F4P(C6F5)CH2](2)-1,3}Cl](+) and, where M = Rh, the singly C-F bond-activated species Me(4)CH(2)C(6)F(4)P(C6F 5)CH2-CH2P(C6F5)(2)}Cl](+).