The self‐assembly properties of nine low‐molecular‐weight gelators (LMWGs) based on bile acid alkyl amides were studied in detail. Based on the results, the number of hydroxyl groups attached to the steroidal backbone plays a major role in the gelation, although the nature of the aliphatic side chain also modulates the gelation abilities. Of the 50 gel systems studied, 35 are based on lithocholic acid and 15 on cholic acid derivatives. The deoxycholic acid derivatives did not form any gels. The gelation occurred primarily in aromatic solvents and the gels manifested typical fibrous or spherical morphologies. The ¹³C cross‐polarized magic angle spinning (CPMAS) NMR spectra measured on the crystalline materials and the corresponding wet organogels were analogous, suggesting that the chemical environments, that is, the intermolecular interactions found in the two materials were similar. The single‐crystal X‐ray structures of all nine bile‐acid amide derivatives studied revealed very similar molecular conformations in the solid state and gave insights into the possible intermolecular interactions in the gel state.

中文翻译：

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胆汁酸烷基酰胺的超分子凝胶化特性的系统调节

详细研究了九种基于胆酸烷基酰胺的低分子量胶凝剂（LMWG）的自组装性能。基于该结果，尽管脂族侧链的性质也调节了凝胶化能力，但是连接至甾族骨架的羟基数目在凝胶化中起着重要作用。在研究的50种凝胶体系中，有35种基于石胆酸，而15种基于胆酸衍生物。脱氧胆酸衍生物没有形成任何凝胶。凝胶化主要发生在芳族溶剂中，并且凝胶表现出典型的纤维或球形形态。在¹³在结晶材料和相应的湿有机凝胶上测得的C交叉极化魔角旋转（CPMAS）NMR光谱是相似的，这表明两种材料中发现的化学环境（即分子间相互作用）相似。研究的所有九种胆酸酰胺衍生物的单晶X射线结构揭示了固态中非常相似的分子构象，并洞悉了凝胶态下可能的分子间相互作用。