The reactions of arachno-[B9H14]− and nido-[B9H12]− with acids: Preparation and structures of chlorononaborates

The unidentified product from the hydride abstraction reaction between [B9H14]− and BCl3 that produces B10H14, [HBCl3]−, and H2 was previously thought to possess a polymeric structure, but has been shown to consist of a mixture of singly-, doubly- and triply-chlorinated analogues of arachno-[B9H14]−. X-ray diffraction analyses indicate that these species co-crystallize in the solid state. These problems of disorder prompted us to prepare the analogous singly-substituted cluster [B9H13Cl]− by a different route. This species was obtained from the reaction between nido-[B9H12]− and anhydrous HCl, and its structure was also determined by X-ray analysis.