Multi-responsive novel phosphamide organogels dominated by a natural diterpene rigid backbone

Abstract

Functional supramolecular organogels with unique properties and morphology can be obtained by designing gelators’s chemical structure. Rosin, an important natural renewable diterpene resource, consists of a rigid ring skeleton and chiral structure similar to triterpenoids and has excellent self-assembly ability in solution. In this paper, four novel rosin-based derivatives were proposed and synthesized in one step by introducing phosphamide groups by using natural rosin as raw material. They could form eleven types of monoamide and diamide organogels in specific solvents. The minimum gelatinization concentration is 50–180 mg/mL. In particular, by adjusting the number and type of phosphamide groups and rigid structures, the morphology and other properties of the gel could be modulated. Two-dimension lamellar and three-dimensional fiber network organogels were obtained and the hydrogen bond and π–π stack were proved to be the most important driving forces for the gelation. What is particularly important is that the gels exhibited multiple stimulus responsiveness, such as temperature, acid-base and anions. Thus, the four dehydroabietylamine phosphamide gelators synthesized by the one-step method provide new ways of designing novel gel-based soft materials for intelligent response, ion detection, etc.