Photosynthetic exciton theory in the 1960s

Theoretical developments in the 1960s concerning the migration of chlorophyll electronic excitation energy through a photosynthetic core antenna to a reaction center are reviewed in three parts. These include the first theory paper whose calculated results were consistent with experiment, the first analytic determination of the mean number of steps in the two-dimensional random walk of a dephased exciton to reach the reaction center, and the first theoretical description of the possible effects of true collective excited states (Frenkel excitons) on the rate of trap-limited migration and trapping. The possible relevance of these developments, particularly the last, to current photosynthesis research is briefly discussed.