title: Imidazolium camphorsulfonamides: chiral catanionic liquid crystals with tunable thermal properties.
abstract: We report the synthesis of novel chiral catanionic liquid crystals bearing camphorsulfonamide substructures. The phase behaviour of these long-chain substituted imidazolium sulphates and sulfonates was investigated using X-ray diffraction (XRD), polarizing optical microscopy (POM) and differential scanning calorimetry (DSC). We observed that the phase behaviour clearly depends on the substitution of both cation and anion. The chiral camphorsulfonamide substructures have an unfavourable influence on the formation of liquid crystalline (LC-) phases. Contrary to N,N'-di-alkyl-imidazolium salts, the formation of LC phases was only observed when both cation and anion are substituted with long alkyl chains (C(12) or C(16)). Furthermore, the phase transition temperatures depend on the chain length of the alkyl groups, as higher phase transition temperatures were observed for compounds bearing longer alkyl chains. However, no macroscopic evidence for the formation of chiral mesophases was obtained.
authors.affiliation: Institut Charles Gerhardt de Montpellier, UMR 5253 CNRS/UM2/ENSCM/UM1, Equipe AM2N, Ecole Nationale Supérieure de Chimie, Montpellier, France.
authors.forename: Eva
authors.initials: E
authors.lastname: Rettenmeier
authors.forename: Alexey
authors.initials: A
authors.lastname: Tokarev
authors.forename: Christophe
authors.initials: C
authors.lastname: Blanc
authors.forename: Philippe
authors.initials: P
authors.lastname: Dieudonné
authors.forename: Yannick
authors.initials: Y
authors.lastname: Guari
authors.forename: Peter
authors.initials: P
authors.lastname: Hesemann