A series of azobenzene–cholesterol organogel compounds (M0–M12) with different spacers were designed and synthesized. The molecular structures were confirmed by 1H NMR and 13C NMR spectroscopy. The rapid and reversible photoresponsive properties of the compounds were investigated by UV–vis spectroscopy. Their thermal phase behaviors were studied by DSC. The length of the spacer plays a crucial role in the gelation. Compound M6 is the only one that can gelate in ethanol, isopropanol and 1-butanol and the reversible gel–sol transitions are also investigated. To obtain visual insight into the microstructure of the gels, the typical structures of the xerogels were studied by SEM. Morphologies of the aggregates change from flower-like, network and rod with different sizes. By using IR and XRD characterization, it is found that intermolecular H-bonding, the solvents and van der Waals interaction are the main contributions to the specific superstructure.
一系列具有不同间隔的偶氮苯 - 胆固醇有机凝胶化合物(M0-M12)被设计并合成。分子结构经过1H NMR和13C NMR光谱确认。通过UV-vis光谱研究了化合物的快速可逆光响应特性。它们的热相行为通过DSC进行了研究。间隔物的长度在凝胶化中起着至关重要的作用。化合物M6是唯一能在乙醇、异丙醇和1-丁醇中凝胶化的化合物,其可逆凝胶-溶胶转变也得到了研究。为了获得对凝胶微观结构的视觉洞察,通过SEM研究了干凝胶的典型结构。聚集体的形态从花状、网络状到不同尺寸的棒状发生变化。通过IR和XRD表征,发现分子间氢键、溶剂和范德华相互作用是特定超结构的主要贡献。