DEHYDROGENATION OF A CYCLOHEXYL GROUP IN TRICYCLOHEXYLPHOSPHINE COMPLEXES OF RUTHENIUM - X-RAY CRYSTAL-STRUCTURE OF [RU(C6H9PCY2)(CF3COO)]2(MU-CF3COO)2(MU-OH2)

RuH(H-2)(OCOCF3)(PCy3)2 (1) is unreactive toward D2 and (t)BuCH = CH2, whereas RuH2(OCOCF3)2-(PCy3)2 (2) reacts instantly with D2 to exchange H-2 for D2 and with cyclooctene to yield cyclooctane and [Ru-(C6H9PCy2)(OCOCF3)]2(mu-OCOCF3)2(mu-OH2) (5). The crystal structure of 5.(C8H14)2 demonstrates the dehydrogenation of a cyclohexyl group of PCy3 and the presence in 3 of a rare exampl of a bridging water molecule strongly hydrogen-bonded to the terminal trifluoroacetato groups. In solution, 5 is shown to adopt three isomeric forms. P2/c, Z = 2, a = 13.034 angstrom, b = 14.751 angstrom, c = 18.261 angstrom, beta = 105.49-degrees, V = 3383 angstrom 3, R = 0.025, R(w) = 0.030 for 3357 reflections with F(o)2 > 3-sigma-(F(o)2).