Bis(Amino Acid) Oxalyl Amides as Ambidextrous Gelators of Water and Organic Solvents: Supramolecular Gels with Temperature Dependent Assembly/Dissolution Equilibrium
作者:Janja Makarević、Milan Jokić、Berislav Perić、Vladislav Tomišić、Biserka Kojić-Prodić、Mladen Žinić
DOI:10.1002/1521-3765(20010803)7:15<3328::aid-chem3328>3.0.co;2-c
日期:2001.8.3
bis(PhgOH) (5a) (Phg denotes (R)-phenylglycine) oxalyl amides are efficient low molecular weight organic gelators of various organic solvents and their mixtures as well as water, water/DMSO, and water/DMF mixtures. The organisational motifs in aqueous gels are dominated primarily by lipophilic interactions while those in organic solvents are formed by intermolecular hydrogen bonding. Most of the gels are thermoreversible
双(LeuOH)(1a),双-(ValOH)(2a)和双(PhgOH)(5a)(Phg表示(R)-苯基甘氨酸)草酰酰胺是各种有机溶剂及其混合物的有效低分子量有机胶凝剂以及水,水/ DMSO和水/ DMF混合物。水性凝胶中的组织基序主要由亲脂性相互作用决定,而有机溶剂中的基序通过分子间氢键形成。大多数凝胶是热可逆的,并且可以稳定许多个月。然而,2a与有机溶剂形成不稳定的凝胶,该凝胶在老化后转变成各种晶体形状。对于某些1a /醇凝胶,发现醇介电常数(ε)和凝胶熔化温度(Tg)之间存在线性关系。所选凝胶的1 H NMR和FTIR光谱研究揭示了温度依赖性网络组装/溶解平衡的存在。在凝胶的1 H NMR光谱中,只能观察到溶解在截留溶剂中的分子。通过使用内标,可以确定溶解的胶凝剂分子的浓度。在FTIR光谱中,同时存在与网络组装和溶解的胶凝剂分子相对应的谱带。这样就可以通过两种方法确定Kgel值。从InKgel与1