The title charge-compensated allyl carbamolybdaborane 3)-C3H5)-3,3-(CO
)(2)-4-SMe2-3,1,2-closo-MoC2B9H10, or [Mo(C3H5)(C4H16B9S)(CO)(2)], has
been synthesized and its solid-state structure determined. In the sol
id state, the conformation of the {Mo(eta(3)-C3H5)(CO)(2)} fragment is
such that the carbonyl ligands are approximately trans to the cage C
atoms and the conformation of the allyl group is exo.