Unique Nanoscale Behavior in the Twist-bend Liquid Crystal Phase of a Flexible Linear Trimer

We synthesized a liquid crystal dimer and trimer, which exhibit the twist-bend liquid crystal phase, and characterized their microscopic and nanoscopic properties to identify distinctions in the nature of their respective twist-bend phases. On the microscopic scale, the twist-bend phases formed of each oligomer appear essentially identical. However, while the liquid crystal dimer exhibits a temperature-dependent variation of its twist-bend helical pitch from 100 – 180 Å, the trimer exhibits a temperature-independent pitch of ~66 Å, the shortest yet reported in the literature. We attribute the surprisingly short, temperature-independent pitch to a specific combination of intrinsic conformational bend of the trimer molecules and a sterically favorable interdigitation of the trimers over a commensurate fraction (two thirds) of the molecular length.