CAS: Near-IR Absorbing Intramolecular Charge Transfer Complexes: Syntheses, Symmetry-Breaking Charge Transfer, and Charge Transfer Reversal by External Stimuli

University Of North Texas, Denton TX

Investigators

Abstract

In this project, funded by the Chemical Structure, Dynamic & Mechanism B Program of the Chemistry Division, Professor Francis D’Souza of the Department of Chemistry at the University is developing new classes of charge transfer complexes able to absorb light in the near-infrared region. The research could lead to materials with novel optoelectronic properties, which are needed for efficient solar energy harvesting devices and luminescent sensors. The project lies at the interface of organic, physical and materials chemistry, and is well suited to the education of scientists at the undergraduate and graduate levels. The project provides extensive teaching and training of graduate students, and undergraduate students. The technical knowledge, problem-solving abilities, and communication skills learned through participating in the project help to strengthen the nation’s high technology workforce while contributing to the energy efficiency of clean energy technologies. Outreach efforts contribute to a highly diversified research group and collaboration with the Elm Fork Education Center to enhance general science education are also part of the project. Professor Francis D’Souza’s group will address several scientific challenges. First, can the absorption of the intramolecular charge transfer complexes be extended into the near-infrared region and beyond by utilizing highly interacting strong electron donor and strong electron acceptor pairs? Second, can nanocarbon materials such as fullerene, endohedral fullerene and single-wall carbon nanotubes be used to enhance near-infrared absorption and emission in these intramolecular charge transfer complexes? Third, Are the appended photosensitizers capable of triggering efficient ultrafast charge separation upon photoexcitation, thereby leading to charge-separated states? Are novel photochemical events such as symmetry-breaking charge transfer observed in the multi-modular symmetric intramolecular charge transfer complexes? Finally, can external stimulus be used to modulate ground and excited state charge transfer in these intramolecular charge transfer complexes? This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.