Dynamics of excited-state evolution in transition metal complexes: Time resolving electron delocalization

Abstract

The excited-state dynamics of a series of aryl-substituted polypyridyl complexes of RuII have been examined. A combination of experimental work and theoretical calculations provide a cohesive physical model for the chromophore dynamics of these compounds in which changes in intraligand electron delocalization is coupled to motion of the peripheral aryl rings during excited-state thermalization. Preliminary femtosecond time-resolved absorption measurements in room-temperature CH3CN solution indicate a time scale of ca. 200 fs for evolution of this delocalized state, and variable-temperature static emission spectra provide additional insights into how solvation dynamics may be coupled to this process.