Designed synthesis of natural rigid dehydroabietylamine-tailored symmetric benzamide organogels by amide bonds and rigid rings coordinated self-assembly strategy

Abstract

Rosin is an important natural renewable diterpene resource, which has the same rigid ring framework and chiral structure as triterpenes which are scarce and endowed with excellent self-assembly ability in solution. Here, a series of natural rigid dehydroabietylamine-tailored symmetric benzamide gelators (Isophthaloyl dehydroabietamide (IRA), Terephthaloyl dehydroabietamide (TRA) and M-benzoyl dehydroabietylamine (MRA)) containing aromatic nuclei and amides have been designed and synthesized by using rosin-based derivatives dehydroabietylamine as raw material in one-step reaction. The organogels with various interesting morphologies such as 200–300 nm rod-like (IRA), micron-scale quadrilateral or hexagonal sheet (TRA) and spiral wound structure (MRA) are constructed by adjusting the number and symmetry of rigid ring and amide. The driving forces of organicgels are the combination of π-π stacking and hydrogen bonding. It is worth noting that the hydrogen bond is much stronger than π-π stacking. The results showed that the orientation and number of the amide bonds has a strong influence on the intermolecular interactions, resulting in huge differences in the aggregation properties, and morphology of the symmetric benzamide gelators. Based on quantum-chemical calculation and powder XRD analysis of xerogels, the formation processes and mechanisms of organicgels are simulated and analyzed. This report presents a valuable approach for the design of natural terpene based functional soft material.