Amino acids derived diacetylene hydrogelators 1 and 2 which have glycine or alanine moiety as head group were synthesized by several steps. The influences on the hydrogen-bonding interaction between amino acids moieties of hydrogelators in the polymerization by UV irradiation were investigated. The glycine-based hydrogel 1 resulted in the generation of stronger absorption peak at 540 nm at room temperature by UV-irradiation. Interestingly, the red color of the glycine-based diacetylene hydrogel 1 was gradually changed into blue color by decreasing temperature. Finally, the absorption band with 640 nm of glycine-based diacetylene hydrogel 1 showed at 77 K. On the other hand, the alanine-based hydrogel 2 had no significant color change at 77 K. These different color changes between the hydrogels 1 and 2 are attributed to the strong intermolecular hydrogen-bonding interaction between glycine moieties of the hydrogelator 1, as confirmed by FT-IR observation. These results indicate that the hydrogen-bonding strength of the self-assembled hydrogel is a strong influence on the degree of polymerization.
由
氨基酸衍生的二炔
水凝胶剂1和2,分别以甘
氨酸或丙
氨酸作为头基,通过多个步骤合成。研究了
水凝胶剂
氨基酸部分在紫外线辐射下聚合时对氢键相互作用的影响。基于甘
氨酸的
水凝胶1在室温下经过紫外线辐射后,生成了在540纳米处更强的吸收峰。有趣的是,甘
氨酸基二炔
水凝胶1的红色随着温度降低逐渐变为蓝色。最终,在77开尔文下,甘
氨酸基二炔
水凝胶1的吸收带在640纳米处显示。另一方面,基于丙
氨酸的
水凝胶2在77开尔文下没有显著的颜色变化。这两种
水凝胶1和2之间的颜色变化差异归因于
水凝胶剂1中甘
氨酸部分之间强的分子间氢键相互作用,这一点通过FT-IR观察得到了证实。这些结果表明,自组装
水凝胶的氢键强度对聚合程度有着强烈影响。