Molecular structures and optical properties of aggregated forms of chlorophylls analyzed by means of magnetic circular dichroism. Magnetic circular dichroism (MCD) spectra were measured on chlorophylls in different aggregation states formed in organic solvents and in pigment-protein complexes. An index which reflects the magnetic dipole contribution of a specific transition is introduced, that is, a ratio of MCD intensity of Faraday B-term (B) to that of dipole strength (D) (B/D). The absolute value of the index is higher in monomeric chlorophyll a and that in monomeric bacteriochlorophyll a. This index changed depending on the aggregation state of bacteriochlorophyll; in the case of the dimer of bacteriochlorophyll a and bacteriochlorophyll d, the value was nearly the half of that of respective monomer, and it decreases further for a higher aggregate of bacteriochlorophyll d. Based on this index, a molecular structure of the primary electron donor in reaction center complexes is discussed.
|Number of pages||14|
|Journal||Spectrochimica Acta - Part A Molecular Spectroscopy|
|Issue number||5 PART 3|
|Publication status||Published - 1996 May|
- Magnetic circular dichroism
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