Non-radiative relaxation of photoexcited chlorophylls: theoretical and experimental study.

ABSTRACT: Nonradiative relaxation of high-energy excited states to the lowest excited state in chlorophylls marks the first step in the process of photosynthesis. We perform ultrafast transient absorption spectroscopy measurements, that reveal this internal conversion dynamics to be slightly slower in chlorophyll B than in chlorophyll A. Modeling this process with non-adiabatic excited state molecular dynamics simulations uncovers a critical role played by the different side groups in the two molecules in governing the intramolecular redistribution of excited state wavefunction, leading, in turn, to different time-scales. Even given smaller electron-vibrational couplings compared to common organic conjugated chromophores, these molecules are able to efficiently dissipate about 1 eV of electronic ene

SUBMITTER: Bricker WP 

PROVIDER: S-EPMC4561917 | biostudies-literature | 2015 Sep

REPOSITORIES: biostudies-literature