Boron di- and tri-cations

Abstract

Previous work on boron di- and tri-cations is reviewed. The structural chemistry of representative examples of these classes of compound has been probed by determination of the single-crystal X-ray structures of [(4-Mepy)₄B]Br₃ and [py₃BH]Br₂. The electronic structures of the polycations [(py)₃BH]²⁺, [(py)₃BBr]²⁺, [(4-Mepy)₃BH]²⁺, [(4-Mepy)₄B]³⁺, [(Me₃P)₃BH]²⁺ and [(Me₃P)₄B]³⁺ have been examined by DFT methods. The atomic charges on these cations were evaluated by Mulliken, natural population analysis (NPA), Hirschfeld and Voronoi deformation density (VDD) methods.