STUDIES ON THE REACTION OF CARBOXYLATO RHODIUM(I) COMPLEXES [RH(ETA(2)-O2CR)(PIPR3)2] (R=CF3, CH3) WITH H-2, O-2, CO, CF3CO2H, ETHENE AND CYCLOPENTADIENE

The complexes [Rh(eta2-O2CR)(PiPr3)2] (R = CF3 2, CH3 3) smoothly react with CO and C2H4 by partial cleavage of the chelating RCO2-Rh bond to give the square-planar 1:1 adducts trans-[Rh(eta1-O2CR)(L)(PiPr3)2] (4-6). With O2, H2 and CF3CO2H, oxidative addition occurs that leads to the formation of the octahedral compounds [Rh(eta2-O2CR)(O2)(PiPr3)2] (7,8), [RhH2(eta2-O2CR)(PiPr3)2] (10, 11) and [RhH(eta1-O2CCF3)(eta2-O2CCF3)(PiPr3)2] (9). Compound 2 reacts with C5H6 to form the ionic product [C5H5RhH(PiPr3)2]O2CCF3 (13) which, after deprotonation with NaH in THF, gives the half-sandwich complex [C5H5Rh(PiPr3)2] (14) in almost quantitative yield.