ORGANOMETALLIC AQUA COMPLEXES .3. OLEFIN AQUA COMPLEXES OF RHODIUM(I)

Dehalogenation of halide precursors [(olefin)RhCl](2) [olefin = ethyle ne, 1,5-cyclooctadiene (GOD), norbornadiene (NBD), 2,3-dimethylbutadie ne (DMB)] in water gave the respective cis-diolefin aqua ions, charact erized by NMR spectroscopy in solution. Attempted isolation of the tos ylate salt [(COD)Rh(H2O)(2)]OTs yielded crystals of (COD)Rh(H2O)(eta(1 )-OTs) characterized by X-ray structural analysis. [(NBD)Rh(H2O)(2)]Sb F6 in the presence of adventitious toluene decomposed into [(NBD)Rh(et a(6)-toluene)]SbF6 and [(NBD)(2)Rh]SbF6, both complexes were isolated and structurally characterized, Ethylene exchange in [(C2H4)(2)Rh(H2O) (2)](+) is fast with k(2) of the order of 10(4)-10(5) s(-1) M(-1). The rate constant for water exchange in [CODRh(H2O)(2)](+) is estimated a s 10(4) s(-1) (Delta G(173)(not equal) approximate to 25 kJ/mol) at 17 3 K.