Singlet excitation energy transfer

KR Naqvi (1980) The mechanism of singlet-singlet excitation energy transfer from carotenoids to chlorophyll. 

Miyatake, T., H. Tamiaki, A.R. Holtzwarth, and K. Schaffner (1999). Artificial lightharvesting antennae Singlet excitation energy transfer from zinc chlorin aggregate to bacteriochlorin in homogeneous hexane solution. Photochem. Photobiol. 69(4), 448 56. 

In Sections 7.3 and 7.4, the temperature dependence of radiationless transitions and the effect of deuteration on the lifetimes of excited electronic states are examined. In Section 7.5, a contribution to time-resolved spectroscopy is presented. In that section, we will discuss a problem dealing with transport phenomena of electronic excitations in doped molecular crystals. The theory of singlet excitation energy transfer uses an effective Hamiltonian to account for intramolecular excited-state depopulation and energy transfer by multistep migration among guest molecules. 

Theory and Experiment of Singlet Excitation Energy Transfer in Mixed Molecular Crystals... 

Gherban, D Kryschi, C., and Kupka, H. (1995) Theory and calculation of singlet excitation energy transfer in mixed molecular crystals. J. Chem. Phys., 102, 9183. 

Subsequent studies (63,64) suggested that the nature of the chemical activation process was a one-electron oxidation of the fluorescer by (27) followed by decomposition of the dioxetanedione radical anion to a carbon dioxide radical anion. Back electron transfer to the radical cation of the fluorescer produced the excited state which emitted the luminescence characteristic of the fluorescent state of the emitter. The chemical activation mechanism was patterned after the CIEEL mechanism proposed for dioxetanones and dioxetanes discussed earher (65). Additional support for the CIEEL mechanism, was furnished by demonstration (66) that a linear correlation existed between the singlet excitation energy of the fluorescer and the chemiluminescence intensity which had been shown earher with dimethyl dioxetanone (67). 

M. Kupryszewska, I. Gryczynski, and A. Kawski, Intramolecular donor-acceptor separations in methionine- and leucine-enkephalin estimated by long-range radiationless transfer of singlet excitation energy, Photochem. Photobiol. 36, 499-502 (1982). 

In the second case, the HEI is formed in one or several reaction steps which are rate-limiting and the interaction of the ACT with this intermediate occurs in a rapid, kineticaUy unobservable, reaction step. Therefore, kinetic data cannot provide evidence of the occurrence of this interaction (Scheme 5). The classical example of this type of activated CL is the peroxyoxalate reaction , for which an electron transfer between a HEI and the ACT has already been postulated by Rauhut (see Section VI.C). In an elegant experiment, Lechtken and Turro confirmed the occurrence of an activated CL process in this reaction, using energy acceptors with different singlet excitation energies (Eg)... 

The condition for transfer of singlet excitation energy from a fluorophore (donor) to another chromophore (acceptor) to occur is spectral overlap of the donor s fluorescence emission spectrum with the acceptor s absorption spectrum. The efficiency of energy transfer E is defined in eq 15... 

This molecule consisted of two photochromes a fulgimide and a dithienylethene. Both of them could isomerize with UV light from the open form to the closed form. And each photo-unit was thermally stable in either isomeric state. Moreover, the photoisomerization of fulgimide could efficiently transfer singlet excitation energy... 

The singlet triplet energy gap, A/isx. in organic biradicals35 182 183 and (inter-molecular) radical ion pairs184-190 has been shown to be a useful indicator of electronic coupling in ET and excitation energy transfer (EET) processes.191-194... 

Singlet-triplet energy transfer Transfer of excitation from an electronically excited donor in a singlet state to produce an electronically excited acceptor in a triplet state. 

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