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Theory of Singlet—Triplet Exciton Fusion
Author(s) -
Rahman T. S.,
Knox R. S.
Publication year - 1973
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.2220580233
Subject(s) - anthracene , singlet state , chemistry , rhodamine 6g , quenching (fluorescence) , singlet fission , reaction rate constant , triplet state , exciton , excited state , radius , photochemistry , atomic physics , molecular physics , physics , molecule , optics , condensed matter physics , fluorescence , quantum mechanics , kinetics , computer security , organic chemistry , computer science
Förster's theory of resonant transfer of energy has been used to calculate the probability per unit time of transfer of energy from an excited singlet to a triplet, raising the latter to a higher triplet. The magnitude of the effect is computed in applications to chlorophyll, rhodamine 6G, and anthracene, and in all cases it is found that the corresponding Förster radius R 0 STis of the order of 40 to 50 Å. The rate constant k ST for singlet—triplet exciton collisions resulting in quenching of the singlet is then calculated. It is found that the theoretical value of R 0 ST , for the case of crystalline anthracene, which is much larger than that predicted by Babenko et al., leads to better agreement with experiment and is to be preferred. Assuming a joint singlet—triplet diffusion constant of 10 −5 cm 2 /s, the rate constant k ST for chlorophyll in solution is predicted to be 4.5 × 10 −11 cm 3 /s.