New triazolium based ionic liquid crystals

Abstract

A set of novel 1,2,3-triazolium based ionic liquid crystals was synthesized and their mesomorphic behaviour studied by DSC (differential scanning calorimetry), POM (polarizing optical microscopy) and SAXS (small angle X-ray scattering). Beside the variation of the chain length (C₁₀, C₁₂ and C₁₄) at the 1,2,3-triazolium cation also the anion has been varied (Br⁻, I⁻, I₃⁻, BF₄⁻, SbF₆⁻, N(CN)₂⁻, Tf₂N⁻) to study the influence of ion size, symmetry and H-bonding capability on the mesophase formation. Interestingly, for the 1,3-didodecyl-1,2,3-triazolium cation two totally different conformations were found in the crystal structure of the bromide (U-shaped) and the triiodide (rod shaped).