Dexter energy transfer

The Dexter energy transfer , also called Dexter transfer or Dexter process for short , is a quantum mechanical mechanism of energy transfer between two molecules , named after David L. Dexter , which is based on an exchange of electrons . Dexter energy transfer plays a role in the light-gathering complex of photosynthesis and in organic semiconductors for lasers or LEDs .

physics

Dexter energy transfer is the dominant triplet-triplet energy transfer. Important prerequisites are the overlapping of the energy functions of donor and acceptor molecules and a distance between donor and acceptor that is less than 1 nm if possible . The total spin of the donor-acceptor pair is retained.

The energy transfer rate k _ET decreases exponentially with increasing distance r from donor and acceptor:

{\ displaystyle k_ {ET} \ propto J \ cdot e ^ {- {\ frac {2r} {L}}}}

,

With

the integral J from the overlapping spectra of donor and acceptor
the penetration depth L of the wave function in the environment ( van der Waals radius ).

Individual evidence

↑ Dexter DL: A theory of sensitized luminescence in solids . In: J. Chem. Phys. . 21, 1953, pp. 836-850.
↑ Laible PD et al. : Detailed Balance in Förster − Dexter Excitation Transfer and Its Application to Photosynthesis . In: J. Phys. Chem. B . 102, No. 9, 1998, pp. 1641-1648. doi : 10.1021 / jp9730104 .
↑ Woggon T. et al. : Organic Electronics in Sensors and Biotechnology (Mc-Graw-Hill Biophotonics Series) . Ed .: Shinar, Joseph; Shinar, Ruth. McGraw-Hill Professional, 2009, ISBN 0-07-159675-5 , Organic Semiconductor Lasers as Integrated Light Sources for Optical sensors, p. 265-298 .

literature

Entry on Dexter (electron exchange) excitation transfer . In: IUPAC Compendium of Chemical Terminology (the “Gold Book”) . doi : 10.1351 / goldbook.D01654 Version: 2.3.1.

[Dexter-1] Dexter DL: A theory of sensitized luminescence in solids . In: J. Chem. Phys. . 21, 1953, pp. 836-850.

[2] Laible PD et al. : Detailed Balance in Förster − Dexter Excitation Transfer and Its Application to Photosynthesis . In: J. Phys. Chem. B . 102, No. 9, 1998, pp. 1641-1648. doi : 10.1021 / jp9730104 .

[isbn0-07-159675-5-3] Woggon T. et al. : Organic Electronics in Sensors and Biotechnology (Mc-Graw-Hill Biophotonics Series) . Ed .: Shinar, Joseph; Shinar, Ruth. McGraw-Hill Professional, 2009, ISBN 0-07-159675-5 , Organic Semiconductor Lasers as Integrated Light Sources for Optical sensors, p. 265-298 .