氢键星形液晶基元的多态性——一项组合密度泛函理论-色散校正（DFT-D）和傅里叶变换红外光谱（FT-IR）的研究

Pfletscher Michael, Wysoglad Janek, Gutmann Jochen S, Giese Michael

Institute of Organic Chemistry, University Duisburg-Essen Universitätsstr. 7 45141 Essen Germany

Institute of Physical Chemistry, University Duisburg-Essen Universitätsstr. 2 45141 Essen Germany.

RSC Adv. 2019 Mar 14;9(15):8444-8453. doi: 10.1039/c8ra09458f. eCollection 2019 Mar 12.

A comprehensive study combining detailed computational analyses with temperature-variable FT-IR experiments was performed in order to elucidate the structure of the hydrogen-bonded liquid crystals based on phloroglucinol and azopyridine in their mesophase. Conformational analysis revealed three relevant conformers: star, λ- and E-shape. The results demonstrate an entropy-driven unfolding mechanism of the assembly. The stability of the conformers is given by intermolecular π-π and dispersion interactions of the azopyridine side chains. Correlating the calculated vibrational frequency with experimental FT-IR spectra suggests a λ-folded conformation of the assemblies as the predominant species in the mesophase.

为了阐明基于间苯三酚和偶氮吡啶的氢键液晶在中间相中的结构，进行了一项将详细的计算分析与变温傅里叶变换红外光谱实验相结合的综合研究。构象分析揭示了三种相关构象：星形、λ形和E形。结果表明该组装体存在熵驱动的解折叠机制。构象体的稳定性由偶氮吡啶侧链的分子间π-π相互作用和色散相互作用决定。将计算得到的振动频率与实验傅里叶变换红外光谱相关联，表明组装体的λ折叠构象是中间相中的主要物种。