New, systematic syntheses of boron hydrides via hydride ion abstraction reactions: Preparation of B2H6, B4H10, B5H11, and B10H14

Abstract

The boron hydrides B2H6, B4H10, B5H11, and B10H14 are prepared in good yields through hydride ion abstraction reactions when the borane anions BH4-, B3H8-, B4H9-, and B9H14- respectively are treated with 1 molar equiv of a Lewis acid BX3 (X = F, Cl, or Br), generally in the absence of a solvent, for reaction periods of 1-4 h. A high-yield (85-90%) method for the conversion of B5H9 to B9H14- is presented as the precursor to the practical conversion of B5H9 to B10H14 (45-50%). Additionally, treatment of the anion BrB3H7- with BBr3 results in the formation of 2-BrB4H9 in low yield (15%). The hydride ion abstraction reactions by BBr3 and BCl3 lead to the new anions HBBr3- and HBCl3-. © 1982 American Chemical Society.