Synthesis and reactivity of an unusual oxidation product of bis[(.mu.-mercapto)(.mu.-thio)cyclopentadienylmolybdenum]

The reaction of a dilute solution of (CpMo({mu}-S)({mu}-SH)){sub 2} (Cp = C{sub 5}H{sub 5}) with 1 equiv of phenylacetylene under air leads to the formation of anti-CpMo(O)({mu}-S){sub 2}Mo(SCH=C(Ph)S)Cp (1) in 20% yield. Both syn and anti isomers of 1 can be synthesized by the reaction of (CpMo(SCH=C(Ph)S)){sub 2} with trifluoroacetic acid under air. The anti isomer has been characterized by an x-ray diffraction study. The complex crystallizes in space group Pna2{sub 1}, with a = 10.284 (6) {angstrom}, b = 15.175 (8) {angstrom}, c = 12.018 (7) {angstrom}, and V = 1875 (2) {angstrom}{sup 3}. The dinuclear complex contains two {mu}-sulfido ligands in a nonplanar Mo{sub 2}S{sub 2} core, a terminal oxo ligand on one CpMo site, and a bidentate styrenedithiolate ligand coordinated to the second CpMo site. The cyclopentadienyl ligands are anti with respect to the metal-metal vector. The terminal oxo ligand in 1 is displaced by sulfide in the reaction with hexamethyldisilthiane. Complex 1 reacts with hydrogen to form water, (CpMo){sub 2}S{sub 4} derivatives, and organic products that result from hydrogenation and hydrolysis of the styrenedithiolate ligand.