Influence of Protonation State on the Excited State Dynamics of a Photobiologically Active Ru(II) Dyad.

Abstract

The influence of ligand protonation on the photophysics of a ruthenium (Ru) dyad bearing the 2-(1-pyrenyl)-1H-imidazo[4,5-f][1,10]-phenanthroline (ippy) ligand was investigated by time-resolved transient absorption spectroscopy. It was found that changes in the protonation state of the imidazole group led to changes in the electronic configuration of the lowest lying excited state. Formation of the fully deprotonated imidazole anion resulted in excited state signatures that were consistent with a low-lying intraligand (IL) triplet state. This assignment was supported by time-dependent density functional theory (TDDFT) calculations. IL triplet states have been suggested to be potent mediators of photodynamic effects. Thus, these results are of interest in the design of Ru metal complexes as photosensitizers (PSs) for photodynamic therapy (PDT).

DOI: 10.1021/acs.jpca.6b05957

Cite this paper

@article{Reichardt2016InfluenceOP, title={Influence of Protonation State on the Excited State Dynamics of a Photobiologically Active Ru(II) Dyad.}, author={Christian Reichardt and Tariq Sainuddin and Maria Waechtler and Susan M A Monro and Stephan Kupfer and Julien Guthmuller and Stefanie Gr{\"a}fe and Sherri A McFarland and Benjamin Dietzek}, journal={The journal of physical chemistry. A}, year={2016}, volume={120 32}, pages={6379-88} }