A de Vries (SmC*) Phase in a Novel Series of Chiral Fluorinated Organosiloxane Liquid Crystals

Fluorenone imidazolium salts as novel de Vries materials

“…[26][27][28][29] De Vries materials have created much interest recently, because ferroelectric displays based on de Vries materials might overcome limitations of current nematic LC displays such as limited resolution and low optical efficiency. [30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47] One of the characteristic features of de Vries materials is their tilting transition without defect generation. These materials show no or only very low layer contraction upon the SmA to SmC phase transition, enabling ferroelectric displays without zig-zag defects caused by the chevron-like arrangement of the molecules in the mesophase.…”

“…These materials show no or only very low layer contraction upon the SmA to SmC phase transition, enabling ferroelectric displays without zig-zag defects caused by the chevron-like arrangement of the molecules in the mesophase. With regard to the design of calamitic liquid crystals displaying SmA and SmC phases and de Vries behaviour most previous work has focused on 5-phenylpyrimidines, 39,41,43,[48][49][50][51][52][53] 2phenylpyrimidines, [54][55][56][57][58] biphenyls, 40,44,[59][60][61][62][63][64] thiadiazoles, 54,65 aroylhydrazones 66 and bent-core mesogens. 37,[67][68][69][70][71][72][73][74] Lemieux and Ivanov have reported independently for non-charged liquid crystals 3-5 that a rigid uorenone core promotes formation of the SmC phase.…”