A C₃-symmetric acylhydrazone-based low molecular weight gelator (BHTP) bearing three pyridine units was synthesized and it was found to form a stable supramolecular gel in the mixture solvent of DMSO–H₂O. The morphology of the gel as observed by FE-SEM showed a dense sheet structure. Hydrogen bonding and π–π stacking between the gelators were determined as the non-covalent interactions for the gelation, which were investigated thoroughly using XRD, UV-Vis, ¹H NMR and FT-IR instruments. BHTP could form pH tolerant supramolecular gels in the widest range of pH values from 1 to 11. The DMSO–H₂O (v : v = 1 : 1) gel exhibited selective response to OH⁻ over a series of other anions through the color change from a white gel to a yellow solution, and the OH⁻ response mechanism was proved by ¹H NMR experiments. In solution, the lowest detection limit of BHTP for OH⁻ was calculated to be as low as 1.62 × 10⁻⁷ M via UV-Vis titration experiments. Finally, encapsulation and controlled release of small molecules such as rhodamine B, crystal violet and methyl orange have been successfully carried out, demonstrating the potential for drug delivery application of this C₃-symmetric supramolecular gel. This work opens a novel avenue for the preparation of supramolecular gel-based multiple functional smart materials.

中文翻译：

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用于小分子控释的氢氧化物响应 C3 对称超分子凝胶的构建

合成了一种带有三个吡啶单元的C ₃对称酰基腙基低分子量凝胶剂 ( BHTP )，发现它在 DMSO–H ₂ O的混合溶剂中形成了稳定的超分子凝胶。FE-SEM 显示出致密的片状结构。凝胶剂之间的氢键和 π-π 堆积被确定为凝胶化的非共价相互作用，使用 XRD、UV-Vis、¹ H NMR 和 FT-IR 仪器对其进行了彻底研究。BHTP可以在 1 到 11 的最宽 pH 值范围内形成耐 pH 值的超分子凝胶。DMSO –H ₂ O (v : v = 1 : 1) 凝胶表现出对 OH ^{- 的}选择性响应通过从白色凝胶到黄色溶液的颜色变化超过一系列其他阴离子，并且通过¹ H NMR 实验证明了 OH ^-响应机制。在溶液中，通过紫外-可见滴定实验计算出BHTP对 OH ^-的最低检测限低至 1.62 × 10 ^-7 M。最后，罗丹明B、结晶紫和甲基橙等小分子的包封和控释已成功进行，证明了这种C _{3 的}药物递送应用潜力-对称超分子凝胶。这项工作为制备基于超分子凝胶的多功能智能材料开辟了一条新途径。