SYNTHESIS AND STRUCTURE STUDIES OF SULFIDO MOLYBDENUM LATE-TRANSITION-METAL CLUSTERS WITH A GENERAL FORMULA CP2MO2M'2-3S2-4(CO)N

Several new bimetallic sulfur clusters, Cp2Mo2Co3S2(CO)7 (3), Cp2Mo2Co2S3(CO)4 (4), Cp2Mo2Co2S2(CO)6 (5), and Cp2Mo2Fe2S4(CO)6 (6), were synthesized from the reaction of late-transition-metal carbonyls and a Mo/S dimer, Cp2Mo2-(SMe)2(CO)2 (1). Overall yields from the reaction are better than those of reported methods. Compound 3 has an unprecedented framework stoichiometry Mo2Co3S2, and 4 contains a μ4-S ligand. The bonding interactions and 4e donor property of the μ4-S ligand are illustrated with EHMO studies. Both 3 and 4 can be viewed as capped butterfly clusters with a Co(CO)3 group or a sulfur atom as the capping group. The geometrical similarity and interconversion among clusters with four, five, and seven framework members are discussed in terms of skeleton electron counting theories. Compound 6 is geometrically an edge-shared bisquare pyramid. This shape gives a less compact structure than those of similar M4S4 cubane clusters. X-ray crystallography data are as follows. 3: monoclinic space group P21/c; a = 8.174(4), b = 18.473 (7), c = 14.436 (11) Å; β = 97.92 (5)°; Z = 4; R = 0.053. 4: monoclinic space group C2/c; a = 15.374 (5), b = 11.888 (7), c = 10.346 (4) Å; β = 103.83 (3)°; Z = 4; R = 0.031. 6: space group P21/c; a = 6.588 (2), b = 16.666 (4), c = 19.834 (5) Å; β = 92.26 (2)°; Z = 4; R = 0.034. © 1990, American Chemical Society. All rights reserved.