Synthesis and characterization of salts of the bis(diisopropylamido)boron(III) cation and attempted reactions to make the corresponding bis(dimethylamido)boron(III) cation

Article abstract of DOI:10.1021/ic00132a049

Bis(diisopropylamino)chloroborane and pure AlCl₃ react under rigorously anhydrous conditions in a one to one ratio to give an ionic compound that can be formulated as [(i-Pr)₂N=B=N(i-Pr)₂]⁺[AlCl₄] ^-. This representation is supported by ²⁷Al, ¹H, ¹³C, and ¹¹B NMR data as well as by IR absorption bands at 1830-1900 cm^-1 assigned to the B=N double bond. Conductivity data are also given for the related compound made from bis(dimethylamino)chloroborane. The [Me₂N=B=NMe₂]⁺ cation was not stable in solution. Evidence is interpreted in favor of either its condensation to bigger units and/or the formation of a molecular compound with the AlCl₄^- anion. Lewis base molecules will add to the tetramethyl cation to give a four-coordinate boron cation.