一种新型的外修含偶氮苯官能团聚苄醚型树状分子凝胶因子合成及性能研究

Synthesis and Property of a New Type of Poly(Benzyl Ether)Dendritic Organogelator Functionalized with Azobenzene Groups

树枝状大分子是一类具有规整、精致三维立体结构的单分散大分子,由于其独特的结构和性能,已成为构建超分子凝胶软材料的理想分子之一。我们设计合成了一种新型的外围含偶氮苯官能团聚苄醚型树状分子凝胶因子PA-G1,其分子结构通过了1H-NMR、13C-NMR和HRMS等手段表征。通过“倒置法”研究了其在12种不同有机溶剂中的成凝胶行为,发现其在乙腈中的最低成凝胶浓度(CGC)为15.8 g/L(2.0%wt),相当于一个树状分子可以固定1.0×10^3个溶剂分子,表现出较优异的成凝胶性能;通过SEM研究了其在不同有机溶剂中的组装微观形貌;进一步通过基于浓度和温度变化的1H-NMR详细研究了其成凝胶机理,证明了芳香环之间的π-π相互作用是其成胶的主要驱动力。

Dendrimers and dendrons are highly branched macromolecules with well-defined molecular architecture and have been widely used as building blocks in the self-assembling of supramolecular gel-phase materials.In this paper,a new poly(benzyl ether)dendritic organogelator containing azobenzene moieties at the tether termini was designed,synthesized and fully characterized by 1H-NMR,13C-NMR and HRMS.The gelation behaviour of the dendritic organogelator(PA-G1)was tested in 12 organic solvents.The dendron PA-G1 was found to be an efficient and versatile organogelator toward various apolar and polar organic solvents with the critical gelation concentrations(CGCs)approaching 2.0 wt%,indicating good gelation ability.The morphology of the xerogel with re⁃spective solvents was investigated by SEM.Further studies revealed that the intermolecular multipleπ-πstacking interactions might be responsible for guiding the self-assembly processes and the gel formation.