Hydrogen Bonded Supramolecular Polymers in Both Apolar and Aqueous Media： Self-Assembly and Reversible Conversion of Vesicles and Gels

• Published in: Chinese journal of chemistry Vol. 29; no. 12; pp. 2597 - 2605
• Main Author: 杜平 孔军 王贵涛 赵新 李光玉 蒋锡夔 黎占亭
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01.12.2011; WILEY‐VCH Verlag; Wiley Subscription Services, Inc
• Subjects: Esters; Hydrocarbons; Hydrogen; hydrogen bond; Methanol; organogel; Polymers; self-assembly; supramolecular polymer; vesicle; 凝胶; 可逆转换; 囊泡; 氢键; 水介质; 自组装行为; 超分子聚合物; 非极性
• ISSN: 1001-604X; 1614-7065
• DOI: 10.1002/cjoc.201100254

In a preliminary letter （Tetrahedron Lett. 2010, 51, 188）, we reported two new hydrazide-based quadruple hydrogen-bonding motifs, this is, two monopodal （la and lb） and five dipodal （2a, 2b and 3a--3c） aromatic hydrazide derivatives, and the formation of supramolecular polymers and vesicles from the dipodal motifs in hydrocarbons. In this paper, we present a full picture on the properties of these hydrogen-bonding motifs with an emphasis on their self-assembling behaviors in aqueous media. SEM, AFM, TEM and fluorescent micrographs indicate that all the dipodal compounds also form vesicles in polar methanol and water-methanol （up to 50% of water） mixtures. Control experiments show that lb does not form vesicles in same media. Addition of lb to the solution of the dipodal compounds inhibits the latter＇s capacity of forming vesicles. At high concentrations, 3b and 3c also gelate discrete solvents, including hydrocarbons, esters, methanol, and methanol-water mixture. Concentration-dependent SEM investigations reveal that the vesicles of 3b and 3c fuse to form gels and the gel of 3c can de-aggregate to form the vesicles reversibly.