Photo-controllable Luminescence from Radicals Leading to Ratiometric Emission Switching via Dynamic Intermolecular Coupling

The development of photoinduced luminescent radicals with dynamic emission color is still challenging. Herein we report a novel molecular radical system (TBIQ) that shows photo-controllable luminescence, leading to a wide range of ratiometric color changes via light excitation. The conjugated skeleton of TBIQ is decorated with steric-demanding tertiary butyl groups that enable appropriate intermolecular interaction to make dynamic intermolecular coupling possible for controllable behaviors. We reveal that the helicenic pseudo-planar conformation of TBIQ experiences a planarization process after light excitation, leading to more compactly stacked supermolecules and thus generating radicals via intermolecular charge transfer. The photo-controllable luminescent radical system is employed for a high-level information encryption application. This study may offer unique insight into molecular dynamic motion for optical manufacturing and broaden the scope of smart-responsive materials for advanced applications.

Automated summary

In this study, a novel photo-controllable luminescent radical system (TBIQ) was reported, which showed a wide range of ratiometric color changes via light excitation. The conjugated skeleton of TBIQ was decorated with steric-demanding tertiary butyl groups, enabling dynamic intermolecular coupling for controllable behaviors. The study revealed that the planarization process of TBIQ's helicenic pseudo-planar conformation after light excitation led to the generation of radicals via intermolecular charge transfer. This photo-controllable luminescent radical system was employed for high-level information encryption, offering unique insights into molecular dynamic motion for optical manufacturing and broadening the scope of smart-responsive materials for advanced applications.