Enhancing Luminescent Transition Metal Complexes: Utilizing Novel, Strong ϖ-Accepting Ligands for Improved Stability and Excited-State Properties.

Luminescent transition metal complexes with highly reactive emissive excited state properties are of significant interest due to their broad range of applications. The key role of ligand design and metal-ligand interactions in designing complexes with desirable properties is widely recognized. While the creation of new ligand frameworks can modify metal-ligand interactions, they often face limitations due to inherent synthetic difficulties. As an alternative, this project proposes the functionalization of simple ligands with substituents as an efficient approach to significantly alter steric and electronic properties, as well as metal-ligand interactions. In this project, we aim to develop a new class of luminescent transition metal complexes with superior π-accepting ligands using super π-acidic and electron-withdrawing substituents. We expect these substituents will enhance luminescent properties and yield blue-shifted emission from an excited state with strong redox potentials. A comprehensive study of the photophysics and electrochemistry of the proposed metal complexes will reveal the impacts of superior π-accepting ligands on coordination chemistry, metal-ligand interactions, and application performance. The chemosensory, device, and photocatalytic applications of the newly developed complexes will also be studied. Beyond the proposed complexes, this project would inspire new ligand developments based on similar designs, which could lead to the synthesis of a large number of transition metal complexes with diverse functional properties and applications.