Synthesis and reactivity of dimolybdathiaborane cluster [(Cp*Mo)(2)B4SH6] (Cp* = eta(5)-C5Me5)

Chemistry and reactivity of dimolybdathiaborane, [(Cp*Mo)(2)B4SH6], 1, obtained from the reaction of 2-mercaptobenzothiazole, [Cp*MoCl4] and [LiBH4.thf], has been explored with dinuclear metal carbonyl [Fe-2(CO)(9)]. As a result, reaction of 1 with [Fe-2(CO)(9)] yielded heterometallathiaborane, [(Cp*Mo)(2)B4H6SFe(CO)(3)], 2 in good yield. Both the new compounds have been characterized in solution by H-1, B-11 and C-13 NMR spectroscopy and the structural types were unequivocally established by X-ray crystallographic analysis of compound 2. Cluster 2 has a bicapped octahedral geometry with the {Fe(CO)(3)} fragment occupying one of the high-connectivity cluster vertexes rather than a capping position. Interestingly, cluster 1 undergoes geometric changes (bicapped trigonal bipyramid --> bicapped octahedron) on the addition of two-electron {Fe(CO)(3)} fragment to 1.