C–H···π Interaction Induced Formation of Microtubes with Enhanced Emission

High luminescent bis(salicylaldehyde)o-phenylenediimine(salophen) microtubes with rectangular cross sections were successfully synthesized by a self-assembly method. Accompanied by the formation of microtubes, a remarkable enhanced emission was observed. Crystal structure analysis and theoretical studies were both investigated in detail. It was found that a conformation change induced by multiple C–H···π interactions between adjacent molecules was responsible for the formation of microtubes. The edge-to-face C–H···π interactions also resulted in molecular structural rigidification, which made salophen a stronger emitter in microtubes.