Ion polarisation-assisted hydrogen-bonded ferroelectrics in liquid crystalline domains

An alkylamide-substituted (-NHCOC10H21) hydrogen-bonded dibenzo[18]crown-6 derivative (1) was prepared to stabilise the ionic channel structure in a discotic hexagonal columnar (Col(h)) liquid crystal. The introduction of simple M+X- salts such as Na+PF6- and K+I- into the ionic channel of 1 enhanced the ionic conductivity of the Col(h) phase of the M+center dot(1)center dot X- salts, with the highest ionic conductivity reaching similar to 10(-6) S cm(-1) for K+center dot(1)center dot I- and Na+center dot(1)center dot PF6- at 460 K, which was approximately 5 orders of magnitude higher than that of 1. The introduction of non-ferroelectric 1 into the ferroelectric N,N ',N ''-tri(tetradecyl)-1,3,5-benzenetricarboxamide (3BC) elicited a ferroelectric response from the mixed Col(h) phase of (3BC)(x)(1)(1-x) with x = 0.9 and 0.8. The further doping of M+X- into the ferroelectric Col(h) phase of (3BC)(0.9)(1)(0.1) enhanced the ferroelectric polarisation assisted by ion displacement in the half-filled ionic channel for the vacant dibenzo[18]crown-6 of (3BC)(0.9)[(M+)(0.5)center dot(1)center dot(X-)(0.5)](0.1).

Automated summary

A novel alkylamide-substituted derivative was synthesized to stabilize the liquid crystal structure and enhance ionic conductivity. Upon introducing simple M+X- salts, the ionic conductivity of the liquid crystal phase was significantly improved.