Electronic resonance with anticorrelated pigment vibrations drives photosynthetic energy transfer outside the adiabatic framework

Proc Natl Acad Sci U S A. 2013 Jan 22;110(4):1203-8. doi: 10.1073/pnas.1211157110. Epub 2012 Dec 24.

Abstract

The delocalized, anticorrelated component of pigment vibrations can drive nonadiabatic electronic energy transfer in photosynthetic light-harvesting antennas. In femtosecond experiments, this energy transfer mechanism leads to excitation of delocalized, anticorrelated vibrational wavepackets on the ground electronic state that exhibit not only 2D spectroscopic signatures attributed to electronic coherence and oscillatory quantum energy transport but also a cross-peak asymmetry not previously explained by theory. A number of antennas have electronic energy gaps matching a pigment vibrational frequency with a small vibrational coordinate change on electronic excitation. Such photosynthetic energy transfer steps resemble molecular internal conversion through a nested intermolecular funnel.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Electron Transport
  • Electrons
  • Energy Transfer
  • Models, Biological
  • Photosynthesis / physiology*
  • Photosynthetic Reaction Center Complex Proteins / chemistry
  • Photosynthetic Reaction Center Complex Proteins / metabolism
  • Quantum Theory
  • Spectrum Analysis
  • Vibration

Substances

  • Photosynthetic Reaction Center Complex Proteins