Effect of Pyrolysis Conditions of Tetraalkylammonium Borohydrides on the Formation of Closo-Dodecaborate

Based on the ¹¹B NMR study of products of the pyrolysis of tetraethylammonium and tetrabutylammonium tetraborohydrides, the formation of higher hydroborates in such processes is shown to be extremely sensitive to the presence of water vapors at a level of 2.6-2.7 kPa. The conditions in which the corresponding \({\mathrm{B}}_{3}{\mathrm{H}}_{8}^{-}\) ${\mathrm{B}}_3{\mathrm{H}}_8^{-}$ and \({\mathrm{B}}_{12}{\mathrm{H}}_{12}^{2-}\) ${\mathrm{B}}_{12}{\mathrm{H}}_{12}^{2-}$ salts are formed by the pyrolysis of Et₄NBH₄ and Bu₄NBH₄ have been found. As a result of this study, a method for Bu₄NB₃H₈ and (Bu₄N)₂B₁₂H₁₂ obtaining with high yields has been developed.