Migrating singlet excitations

Morrison et al. have also studied the photolytic behavior of chloro-substituted benzobicyclo-compounds and have proposed (n + singlet excited state which initiates C-Cl bond cleavage prior to a rapid electron transfer [84, 85], Quantum efficiencies of C-Cl cleavage in /i-substituted (48) and (49) are greater for exo- than for endo-cleavage [86, 87]. The products are characterized by extensive syn-migration, and the formation of... 

The characteristics of fluorescence also provide information on the lifetime of the excited singlet state of chlorophyll in vivo and thus on the time available for migration of excitations. Specifically, approximately 1 to... 

Temperature Dependence of Singlet Excitation Energy Migration in Liquid Benzene as Revealed by Picosecond Laser Photolysis... 

Singlet excited state energy migration in aromatic polymers has been proposed to be important for many years (1). There remains, however, considerable disagreement (1, ) as to the extent of excitation mobility, and little information 3) is available as to the time-scale of energy migration. 

Figure 4.4 Schematic illustration for competing radiative, transfer and migration processes which can occur after singlet excitation. Energy quantum absorbed by the chromophore can be dissipated by single chromophore, monomer emission, hVf, or by dimer chromophore, excimer emission, hv, or it can migrate along the polymer chain, and/or the excitation energy can be transferred to an acceptor molecule.

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