Resonance Raman Studies in Photosynthesis — Chlorophyll and Carotenoid Molecules

Abstract

After a short introduction to the physical principles that govern resonance Raman spectroscopy, the various possibilities of this technique for studying (bacterio)chlorophyll and carotenoid molecules within photosynthetic systems are briefly discussed. Marker bands for coordination state of the central Mg atom and for the interaction state of the various carbonyl of (bacterio)chlorophyll molecules are described. A series of examples are given, illustrating how resonance Raman spectroscopy may help in: (1) assessing the molecular structure of achlorin-type electron carrier; (2) precisely determining the configuration of a protein-bound carotenoid molecule; (3) measuring the interaction strength of the different carbonyl substituents of (bacterio)chlorophyll in a given proteic binding site; and (4) obtaining information on the electronic excited states involved in the photosynthetic process. Literature concerning the application of time-resolved resonance Raman to bacteriochlorophyll and carotenoid molecules in photosynthetic systems is also reviewed.