Reversible energy transfer between

Reversible energy transfer between monomeric and dimeric forms of rhoda-mine 6G in ethylene glycol has been observed" and the concentration dependence of the overall fluorescence quantum yield has been modelled by Monte-Carlo simulations. Triplet energy transfer in disordered polymers has been analyzed on the basis of Bassler s model in which the trap energies have a Gaussian distribution." Energy transfer has also been observed in mono-layers and for photoswitchable molecular triads." The structural requirements for efficient energy transfer from a carotenoid to chlorophyll have been... 

The sensor for the measurement of high levels of CO2 in gas phase was developed, as well90. It was based on fluorescence resonance energy transfer between 0 long-lifetime ruthenium polypyridyl complex and the pH-active disazo dye Sudan III. The donor luminophore and the acceptor dye were both immobilized in a hydrophobic silica sol-gel/ethyl cellulose hybrid matrix. The sensor exhibited a fast and reversible response to carbon dioxide over a wide range of concentrations. 

At s = 0 the concentration corrections in Eq. (3.667) become the rates of excitation quenching by any partner that does not belong to a given couple (reactant pair). These bachelors compete for an excitation with the reactants in a couple when they move apart for a while between successive recontacts. Similar results were obtained with the many-particle theory of diffusion-influenced reactions based on the revised superposition approximation and became known as MPK1 [51]. The authors were the first who managed to obtain concentration corrections to the IET result for the kinetics of reversible energy transfer. In a subsequent modification of their theory, named MPK3 [126], the same authors reached the full correspondence with MET. 

Figure 2. Schematic representation oF electron, hole, and triplet energy transfer between the localized HOMO and LUMO orbitals of the donor and the acceptor. Note that the above diagram also applies to the exchange-mediated singlet excitation transfer if the spin of the electron in the LUMO orbital is reversed.

In a second example the discrete time-reversible propagation scheme for mixed quantum-classical dynamics is applied to simulate the photoexcitation process of I2 immersed in a solid Ar matrix initiated by a femtosecond laser puls. This system serves as a prototypical model in experiment and theory for the understanding of photoinduced condensed phase chemical reactions and the accompanied phenomena like the cage effect and vibrational energy relaxation. It turns out that the energy transfer between the quantum manifolds as well as the transfer from the quantum system to the classical one (and back) can be very well described within the mixed mode frame outlined above. 

Park, P.J., Lee, S. Diffusion-influenced reversible energy transfer reactions between polymers. J. Chem. Phys. 2001,115, 9594. 

The lifetimes range from 0.8 to 18.1 ps. A supramolecular structure has been assembled around a central zinc(ii) cation in such a way that the metal complex is held close to a pyrene unit [191]. Here, the triplet lifetime of the metal complex is somewhat enhanced because of reversible triplet energy transfer between the two chromophores. The pyrene unit can be replaced with other chromophores provided the triplet energy levels can be balanced. Thus, Castellano et al. [192] have reported prolonged triplet lifetimes for complexes 52 and 53. 

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