SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF THE MU-4-S HETEROMETALLIC CLUSTER (ETA-5-C5H4CH3)FE3CO(MU-4-S)(CO)11

The new mu4-Sheterometallic cluster (eta5-C5H4-CH3)Fe3Co(mu4-S)(CO)11 was synthesized in high yield by the addition of (eta5-C5H4CH3)Fe(CO)2 (derived from (eta5-C5H4CH3)Fe(CO)2Cl) to HFe2Co(mu3-S)(CO)9 at room temperature. The cluster was characterized by elemental analyses, IR, and NMR as well as X-ray diffraction analysis. It crystallizes in the monoclinic space group P112(1)/n, a = 8.259(1) angstrom, b = 12.832(2) angstrom, c = 21.408(3) angstrom, gamma = 90.81(1)degrees, V = 2268.4(6) angstrom3, Z = 4, and D(c) = 1.89 g.cm-3. Structure solution and refinement were based on 2367 independent reflections with I greater-than-or-equal-to 3.0sigma(I) (Mo Kalpha, lambda = 0.710 73 angstrom) and converged at R = 0.0447 (R(w) = 0.0399). The mu4-S cluster is proposed as an example of intermediates in electrophilic addition-substituent elimination, and the existence of its isoelectronic analogues (eta5-C5H5)MoFe2Co(mu4-S) (CO)12 and (eta5-C5H4CH3)MoFe2Co-(mu4-S)(CO)12 also is proposed.