Synthesis and structural characterization of an open cage dithiatungstaborane [(CPW)(2)B4H4S2] cluster

Reaction of (CpMCl4)-M-#, (1 or 2) [(1): M = Mo, Cp-# = Cp* (Cp* = eta(5)-C5Me5) and (2): M = W, CP# = Cp (Cp = eta(5)-C5H5)] with excess of [LiBH4 center dot thf] followed by thermolysis with excess of [HS(CH2)(n)SH] (n = 2 or 3), leads to the formation of [(CP*Mo)(2)B4H4S2] (3) or [(CPW)(2)B4H4S2] (4) respectively. Corresponding to (3) and (4), the compounds [(M)(2)B5H9] (M = CpW, (5) or Cp*Mo, (6)) are isolated as major product in both the cases. These new compounds have been characterized in solution by mass, H-1, B-11, C-13 NMR spectroscopy. The structural types have been unequivocally established by X-ray crystallographic analysis of compounds (4).