Chalcogen-linked liquid crystal dimers for twist-bend nematogens

Abstract

Herein, we report twist-bend nematic (NTB) liquid crystals (LCs) based on chalcogen linkages, thioether (C-S-C) and selenoether (C-Se-C). Due to the smaller bond angles of them than those of typical methylene (C-CH2-C) and ether (C-O-C), thioether- and selenoether-linked dimers with odd central spacers form more bent geometries than their methylene- and ether-linked counterparts, which are expected to be useful for formation of the NTB phase. The molecular design for forming the NTB phase, phase behavior, and the helical pitch examination using tender resonant X-ray scattering at the sulfur K-edge are described.