Photofunctional Rhenium(I), Ruthenium(II), and Iridium(III) Complexes as New Bioorthogonal Probes, Imaging Regents, and Photocytotoxic Agents

We have a long-standing interest in the exploitation of the intriguing photophysical and photochemical properties of luminescent rhenium(I), ruthenium(II), and iridium(III) complexes as versatile tools for chemical biology. For example, the highly environment-sensitive emission properties of these metal complexes have facilitated the development of luminescent molecular probes and imaging reagents for live cells. Also, the triplet excited states of many of these complexes can sensitize the formation of singlet oxygen, which has been utilized in the design of new photocytotoxic agents. In this presentation, our recent designs of luminescent transition metal complexes containing a dibenzocyclooctyne, tetrazine, or nitrone unit as bioorthogonal probes will be introduced. The use of these complexes as phosphorogenic sensors, imaging reagents, and photodynamic therapeutics will also be described.