Photoinduced electron transfer in mechanically interlocked suitane systems†
Suitanes, a new class of two-component mechanically interlocked systems, have recently been developed. In this work, we report a detailed study of photoinduced electron-transfer processes in suitanes consisting of a 3-fold symmetric pyridinium-based (HC6+·6PF6−) cage and substituted benzotrithiophenes, as well as other polycyclic aromatic guests. Our analysis of the electronic properties of these complexes shows that electron transfer is favorable for complexes of HC6+·6PF6− with strong donors, such as thiatruxene, benzotrithiophenes, and benzotrifuran. The photoinduced electron transfer for these complexes occurs on the picosecond time scale. On the contrary, electron transfer does not occur in complexes of HC6+·6PF6− with benzotristhiazole and benzotrisoxazole. Our results open perspectives for the future design of mechanically interlocked systems for application in photovoltaic devices.