Abstract
The competition between excited state deactivation processes in mono and double-arm push-pull systems bearing pyridine, furan or thiophene (electron donors) and nitro groups (electron acceptors) was investigated in several solvents through nanosecond and femtosecond transient absorption spectroscopy. Triplet population is the main deactivation pathway for the mono-arm compounds. The large triplet production is mainly ascribed to 3(n,π*) states almost isoenergetic to S1, introduced by nitro groups, as predicted by TD-DFT calculations. The large triplet population may indeed be exploited to produce long-lived excitons for photovoltaic and optoelectronic applications. Two-arm furan and thiophene derivatives instead undergo strong ultrafast intramolecular charge transfer (ICT), which is responsible for their appreciable two-photon absorption cross-sections. In this case, significant fluorescence and singlet oxygen quantum yields are obtained, making these two compounds interesting as potential traceable photosensitizers in photodynamic therapy.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.