New tertiary phosphine derivatives of Os3(CO)12: X-ray structures of 1,2-[Os3(CO)10{PhP(o-Tol)2}2], 1,2,3-[Os3(CO)9{(4-FC6H4)3P}3], 1,2,3-[Os3(CO)9{PhP(Cy)2}3] and [Os3(μ-OH)2(CO)8{(4-FC6H4)3P}2]

Reactions of 1,2-[Os-3(CO)(10)(NCMe)(2)] (1) with tertiary phosphines such as tris(4-fluorophenyl)phosphine (4-FC6H4)(3)P, bis(o-tolyl)(phenyl)phosphine PhP(o-Tol)(2) and dicyclohexyl(phenyl)phosphine PhP(Cy)(2) have been examined at room temperature and found to yield the di- and tri-substituted products 1,2-[Os-3(CO)(10)(PR3)(2)] {(2), PR3 = (4-FC6H4)(3)P; (3), PR3 = PhP(o-Tol)(2); (4), PR3 = PhP(Cy)(2)} and 1,2,3-[Os-3(CO)(9)(PR3)(3)] {(5), PR3 = (4-FC6H4)(3)P; (6), PR3 = PhP(o-Tol)(2); 7, PR3 = PhP(Cy)(2)} as the major products, in addition to the dihydroxyl-bridged complexes 1,2-[Os-3(CO)(8)(PR3)(2)(mu-OH)(2)] {(8), PR3 = (4-FC6H4)(3)P; (9), PR3 = PhP(o-Tol)(2); (10), PR3 = PhP(Cy)(2)} in trace amounts. Compounds (2)-(10) have been characterized by a combination of elemental analyses, infrared, NMR and mass spectral data together with single crystal X-ray diffraction studies for (3), (5), (7) and (8).