STERIC EFFECTS IN OXIDATIVE ADDITION AND REDUCTIVE ELIMINATION-REACTIONS OF RHODIUM PENTAFLUOROPHENYLTHIOLATE COMPLEXES

The complexes [cis-Rh(SC6F5)(PPh3)2(L)] (L = py, 3-Mepy, isoquin, N-MeIm; py = pyridine, 3-Mepy = 3-methylpyridine, isoquin = isoquinoline, N-MeIm = N-methylimidazole) readily undergo oxidative addition of HR (R = H, SC6F5, C2Ph) to give [RhH(R)(SC6F5)(PPh3)n(L)3-n] (n = 1,2) whereas the complexes [cis-Rh(SC6F5)(PPh3)2(L')] (L' = 2-Mepy, 2,6-Me2py, quin; 2-Mepy = 2-methylpyridine; 2,6-Me2py = 2,6-dimethylpyridine, quin = quinoline) react only when R = C2Ph. Where conditions favour the formation of [RhH(R)(SC6F5)(PPh3)n(L')3-n] reductive elimination of H2 (R = H) or C6F5SH (R = SC6F5, C2Ph) occurs.