通过神奇甲基效应打破反转对称性
Broken Inversion Symmetry via a Magic Methyl Effect
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中文总结 AI 辅助
本研究发现1,3-二氧六环5位的甲基效应可打破反转对称性，使极性液晶的极性有序起始温度最高提升120℃，为液晶自发偶极有序提供了通用分子设计策略。
中文摘要 AI 辅助
极性液晶是分子偶极组织成铁电或反铁电态的流体相，其分子设计空间受高度约束，微小改变即可完全抑制极性组织。本文证实，与预期相反，在1,3-二氧六环的5位引入甲基，可大幅提高极性有序的起始温度；该效应可在多个液晶家族间转移，部分案例中甲基化衍生物出现极性相而其母体无此相。在8组匹配对中，5-甲基可将1,3-二氧六环材料的极性有序起始温度最高提升120℃，为增强和实现液晶中自发偶极有序提供了简单通用的分子设计策略。
英文摘要
Polar liquid crystals - fluid phases in which molecular dipoles organise into ferro- or antiferroelectric states - present a highly constrained molecular design space, where small changes can entirely suppress polar organisation. Here we demonstrate, contrary to expectations, that installation of a methyl group in the 5-position of a 1,3-dioxane ring substantially increases the onset temperature of polar order. Remarkably, this effect proves transferable across several liquid-crystal families, including examples where the methylated derivative exhibits a polar phase whereas its parent compound does not. Across 8 matched pairs, we find that a 5-methyl group can enhance the onset temperature of polar order in 1,3-dioxane materials by up to 120 °C. These findings establish a simple and general molecular design strategy for enhancing and enabling spontaneous dipolar ordering in liquid crystals.
