A direct measurement of the kinetics of intramolecular photoinduced metal-metal charge transfer has been made, i.e. (NH3)5RuIIINCFeII(CN) 5 - ⇄kET hv (NH3)5RuIINCFeIII(CN) 5 - where the solvent is H2O or D2O and kET signifies the reverse-electron-transfer (ET) rate coefficient. The apparent reverse-electron-transfer kinetics are nonexponential with a limiting rate constant, klim = k(t) where t → ∞, equal to (8 ± 3) × 1011 s-1. This is close to the theoretical predictions from the model of Sumi and Marcus (classical vibrational modes), kET,SM = 1013 and 5 × 1012 s-1, and from the model of Jortner and Bixon (quantum mechanical vibrations), kET,JB = 1-2 × 1012 s-1, The parameters required for these theories were estimated by resonance Raman spectroscopy, static absorption spectroscopy, and recently published transient Stokes shift measurements.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry