Facile synthesis of the dodecahydridododecaborate (B12H122-) from borane Lewis base adducts

Polyhedral boranes are a class of well-known boron molecular clusters widely used in energy, chemistry, medicine, and materials science because of their unique physical and chemical properties. Great efforts have been made in the past decades to find more effective synthetic methods for this important class of boron compounds. However, existing synthetic methods suffer from low efficiency and low selectivity. Herein, we report a facile one-pot synthesis of [(CH3)3S]2B12H12 with moderate yields at mild conditions. The mechanisms for the multi-step chemoselective synthesis of B12H122- without other by-products are elucidated based on theoretical results and our previous work. The Lewis base used in B-H bond condensation reaction, which acts as a hydrogen or to balance the newly generated polyhedral borane charges, is proposed and studied in detail. The current study has led to a more effective and selective synthetic method for B12H122- and has also implicated the syntheses of other new polyhedral boranes.