1 research outputs found
Influence of Protonation State on the Excited State Dynamics of a Photobiologically Active Ru(II) Dyad
The influence of ligand protonation
on the photophysics of a ruthenium
(Ru) dyad bearing the 2-(1-pyrenyl)-1<i>H</i>-imidazo[4,5-<i>f</i>][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)