Bridged Heterocyclium Dicationic closo-Icosahedral Perfluoroborane, Borane, and Carborane Salts via Aqueous, Open-Air Benchtop Synthesis

Thirteen bridged triazolium and imidazolium dicationic salts, which uniquely pair closo-icosahedral perfluoroborane [B12F12]2−, borane [B12H12]2−, or carborane [CB11H12]− anionic species with unsaturated bridged heterocyclium dications, were synthesized using an aqueous benchtop method. This considerably extends the scope of a reported aqueous synthesis of binary [heterocyclium]2[B12H12] and [heterocyclium][CB11H12] salts. Also, the one-step preparation of five new precursor bridged heterocyclium dicationic dihalide salts using conventional procedures and in one case a microwave-assisted method is described.