RHODIUM PENTAFLUOROPHENYLTHIOLATE COMPLEXES DERIVED FROM [RH2(MU-SC6F5)2(PPH3)4]

The thiolate bridges of [Rh2(mu-SC6F5)2(PPh3)4] are readily split by a variety of phosphines, phosphites and nitrogen-containing compounds to give [Rh(SC6F5)(PR3)3], [Rh(SC6F5){P(OR')3}3], [cis-Rh(SC6F5)(PPh3)2(L)] and [cis-Rh(SC6F)(PPh3)2(L')], (PR3 = PMe2Ph, PMePh2; P(OR')3 = P(OMe)3, P(OEt)3; L (sterically nonhindering) = pyridine, 3-methylpyridine, isoquinoline, N-methylimidazole, acetonitrile; L' (sterically hindering) = 2-methylpyridine, 2,6-dimethylpyridine, quinoline). With H-2 under ambient conditions both [Rh(SC6F5)(PR3)3] and [cis-Rh(SC6F5)(PPh3)2(L)] combine reversibly, [cis-Rh(SC6F5)(PPh3)2(L')] does not react and [Rh(SC6F5)(P(OR')3}3] (in the presence of free P(OR')3) is converted into [RhH{P(OR')3}4]. [Rh(SC6F5)(PR3)3] and [cis-Rh(SC6F5)(PPh3)2(L)] react with phenylacetylene to give [RhH(SC6F5)(C2Ph)(PR3)3] and [RhH(SC6F5)(C2Ph)(PPh3)2(L)], respectively, while with C6F5SH [cis-Rh(SC6F5)(PPh3)2(L)] forms [RhH(SC6F5)2(PPh3)(L)2], and further reaction gives [Rh(SC6F5)3(L)3]. Although [cis-Rh(SC6F5)(PPh3)2(L')] is unreactive towards C6F5SH it combines with PhC2H with loss of C6F5SH yielding [trans-Rh(C2Ph)(PPh3)2(L)]. Other reagents which split the [Rh2(mu-SC6F5)2(PPh3)4] bridge are carbon monoxide and t-butyl isocyanide. Products were characterised by H-1 and P-31 NMR spectroscopy and in many cases were not isolated.