Microbelts and flower-like particles of hexakis-(4-(5-styryl-1,3,4-oxazodiazol-2-yl)-phenoxy)-cyclotriphosphazene: self-assembly and photoreaction

Abstract

Recently, we have reported the self-assembly of nanobelts and microbelts originating from the organic–inorganic hybrid molecule hexakis-(4-(5-phenyl-1,3,4-oxazodiazol-2-yl)-phenoxy)-cyclotriphosphazene (HPCP) by a simple solution method. Inspired by [2 + 2] photodimerization, our group has further attempted to verify the proposed self-assembly mechanism of oxadiazole-containing cyclotriphosphazene by solid-state photochemical reaction. We modified the molecular structure of HPCP, introducing a vinyl group into it to obtain a new oxadiazole-containing cyclotriphosphazene, hexakis-(4-(5-styryl-1,3,4-oxazodiazol-2-yl)-phenoxy)-cyclotriphosphazene (HSCP). The microbelts and flower-like particles of HSCP were self-assembled through a simple solvent exchange process by exploiting the π–π interactions between neighboring HSCP molecules as the driving force. The as-prepared materials were capable of [2 + 2] photodimerization and shape maintenance, as well as forming insoluble fluorescent materials. The self-aggregating and photoreaction properties of HSCP were characterized by UV-vis, FESEM, TEM, ¹H-NMR, etc.