Designing dicationic organic salts and ionic liquids exhibiting high fluorescence in the solid state.

Dicationic ionic liquids (DILs) are emerging as a powerful, next-generation approach to designing applied ILs because of their superior physicochemical properties as well as their diverse complexity and tunability for task specific applications. DILs are scarce in the literature compared to monocationic ILs (MILs), and one of their main issues is their expected tendency to possess higher melting temperatures. A series of 1,4-bis[2-(4-pyridyl)ethenyl] benzene and 1,4-bis[2-(2-pyridyl)ethenyl]benzene quaternary salts (Q-BPEBs) with different counterions (bromide, tosylate, and triflimide) and carbon chain lengths (C, C, and C) have been synthesized for their potential as DILs with strong photoluminescent properties in the solid state.