What is the method of choice to estimate the RedOx potential of excited states for phosphorescent compounds? Whereas the method for fluorescent molecules seems clear and simple, it is not applicable to phosphorescent molecules (there is usually no overlap between absorption / emission). From my understanding the procedure starts at the respective RedOx potentials of the ground state, and adds/ subtracts at least the energy of the emission band. In principle this number is accessible experimentally by either testing a series of reductive / oxidative quenchers, or by special electrochemical techniques (AC, pulsed light) - but none of these are standard methods.

To get a rough estimate, some people use the (energy weighted) mean between absorption and emission, but my feeling is that gives too high values. Other say use the onset of emission - but how is that defined?