I have characterized this electronic structure by a number of static and nanosecond timescale techniques. The apparent inconsistency of this result with static absorption can be rationalized by examining nanosecond transient absorption and electrochemical results. These studies are an essential prerequisite to interpretation of dynamics on a subnanosecond timescale. Having determined the effects of compositional changes on electronic structure, the effects of electronic structure changes on dynamics can be explored. To this end, I am currently applying pump-probe femtosecond transient absorption spectroscopy to gain insight into ultrafast relaxation mechanisms and timescales.
Initial results indicate a concerted movement across excited-state potential energy surfaces.
This is contrary to the common notion of stepwise excited-state evolution, in which vibrational relaxation, internal conversion, and intersystem crossing occur in discrete steps and on discrete timescales.