CAREER: Control of Intramolecular Long-Range Charge-Transfer Emission

University Of Connecticut, Storrs CT

Investigators

Abstract

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2). WIth support from the Chemical Structure, Dynamics & Mechanisms B Program of the Chemistry Division, Tomoyasu Mani of the Department of Chemistry at the University of Connecticut is developing strategies for producing and controlling intramolecular long-range radiative charge recombination or charge transfer (CT) emission in a condensed phase. Molecules that exhibit efficient intramolecular long-range CT emission have the potential to: (1) transform existing tools such as organic light-emitting diodes and biomedical imaging probes and (2) lead to new quantum technologies that leverage their unique responses to a magnetic field and chirality. Educational activities are slated to develop experimental photochemistry modules that introduce the basic concepts of chemistry to high school and lower division undergraduate students. The modules will be implemented in various programs, including an international workshop for high school students and undergraduate general chemistry laboratories, to encourage such early stage students to consider pursuing careers in science, technology, engineering, and mathematics (STEM) fields. Reports of CT emission from long-range intramolecular analogs are scarce; therefore, the necessary knowledge to produce efficient long-range CT emission is lacking. This CAREER project uses a series of well-defined donor−bridge−acceptor (D−B−A) molecules and a multitude of spectroscopic and computational methods to generate a comprehensive dataset for assessing the validity of the current theoretical framework, thus providing an opportunity to extend existing formalisms further. This work seeks to address knowledge gaps present in the fields of electron transfer, spin chemistry, and materials design for applications that employ CT emission, creating new opportunities for advancement. The specific objectives are: (1) to establish strategies to maximize long-range CT emission in D−B−A systems by clarifying the key parameters like energy levels and geometry; (2) to control long-range CT emission by external stimuli such as magnetic field and chirality; and (3) to develop interactive photochemistry modules for high school students and lower division undergraduate students, to introduce students to chemistry concepts associated with recent advances in photochemistry and photophysics. 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.