Crystal and molecular structure of series of triphilic ionic liquid-crystalline materials based on the 1,2,4-triazolium cation

Abstract

Results from the determination of sixteen X-ray single crystal structures are reported for a series of 3-(4-alkoxyphenyl)-5-perfluoroalkyl-2,4-dimethyl-1,2,4-triazolium salts with tetrafluoroborate, triflate or bistriflimide anions, in which the lengths of the alkoxy and perfluoroalkyl chains are varied systematically. On account of these cations having a hydrocarbon, fluorocarbon and ionic part, they are classified as triphilic. All of the tetrafluoroborate salts crystallised in the P2₁/c space group, most as acetone solvates, while for the bistriflimide salts, four different space groups were found although all contained a P2₁ screw axis often with additional symmetry elements. Of the triflates, two crystallised in space groups with a P2₁ screw axis and two in P. The organisation in the crystalline state tended to reflect the triphilic nature of the materials with cations and anions associating in repeating motifs, while the rest of the space was occupied by either hydrocarbon or fluorocarbon domains with only two exceptions.