Theoretical study of conformational aspects, excited states and directional energy transfer: The Terphenylene, Diphenylhexatriene and Quinquethiophene triad included in PHTP nanochannels

The limited one-dimensional space of nanochannels of the supramolecular Perhydrotriphenylene (PHTP) matrix host induce changes on the structure of included molecules that affect some of their properties. A combination of Density Functional Theory and semi-empirical methodologies is used to study the structural changes, the electronic excited states and the energy transfer processes between the triad of oligomers Terphenylene (P3), Diphenylhexatriene (DPH) and Quinquethiophene (T5) included in PHTP. Details of the conformational aspects of the oligomeric guest species have been obtained assuming a rigid matrix approach for the PHTP host. Optimal geometries were considered to study excited states and processes for the P3 → DPH → T5 chain of two-steps transfer of energy from the UV to the visible. Trends for the dominant directional mechanism for the energy transfer have been resolved from a theoretical point of view.