Dexter (electron exchange) excitation transfer

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, $k ET$ , is given by:

$k ET ∝ h 2 π P 2 J e −2 r L$

where $r$ is the distance between donor (D) and acceptor (A), $L$ and $P$ are constants not easily related to experimentally determinable quantities, and $J$ is the spectral overlap integral. For this mechanism the spin conservation rules are obeyed.