Excitation transfer occurring as a result of an electron exchange mechanism. It requires an overlap of
the wavefunctions of the energy donor and the energy acceptor. It is the dominant
mechanism in
triplet-triplet energy transfer. The transfer
rate constant,
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, is given by:
where
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is the distance between donor (D) and acceptor (A),

and
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are constants not easily related to experimentally determinable quantities, and

is the
spectral overlap integral. For this mechanism the spin conservation rules are obeyed.
Source:
PAC, 1996, 68, 2223
(Glossary of terms used in photochemistry (IUPAC Recommendations 1996))
on page 2235
Cite as:
IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by
A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997).
XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic,
J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8.
https://doi.org/10.1351/goldbook.