A nido-6-manganadecaborane salt

A new manganadecaborane has been isolated as a previously unsuspected produ ct from the reaction of [Mn(CO)(5)Br] with K[B9H14]. The anion of tetrabuty lammonium 5-bromo-6,6,6-tricarbonyl-6-manganadodecahydrodecaborate(1-), (C1 6H36N)[Mn(B9H12Br)(CO)(3)], has a nido cage structure. The Mn atom is bonde d through three B-Mn bonds of similar length [2.221 (4), 2.224 (3) and 2.23 6 (3) Angstrom] and two bridging H atoms. The position of the bromo substit uent breaks the twofold symmetry of the cage found in simple analogues, and this is reflected in the B-B bond parameters.