Structure and Properties of Substituted Imidazolium, Triazolium, and Tetrazolium Poly(1,2,4-triazolyl)borate Salts

Abstract

Azolium poly(1,2,4-triazolyl)borate salts were prepared by using a simple and highly effective method. The hydrotris(1,2,4-triazolyl)borate organic salts were synthesized in high yields by metathesis reactions of Ag[HB(tz)3] with substituted imidazolium, triazolium, and tetrazolium iodides. Barium dihydrobis(1,2,4-triazolyl)borate, Ba[H2B(tz)2], was used as a precursor to prepare substituted imidazolium and triazolium dihydrobis(1,2,4-triazolyl)borates by reaction with azolium sulfates to form dihydrobis(1,2,4-triazolyl)borate salts. The dihydrobis(1,2,4-triazolyl)borate and hydrotris(1,2,4-triazolyl)borate anions, when paired with different azolium cations, gave rise to salts with interesting crystalline and physicochemical properties. These new borate salts melt at relatively low temperatures to give thermally stable ionic liquids. Some of them exhibit conductivities similar to that of KCl in acetonitrile−water mixtures.