Energy transfer, intramolecular reactions

Excitation of [33] in the dimethoxybenzene part leads, after very efficient Intramolecular triplet energy transfer, to reaction of the norbornene part of the molecule. 

Atomic and Molecular Collisions Coherent Control of Chemical Reactions Energy Transfer, Intramolecular Ion Kinetics and Energetics Kinetics, Chemical Molecular Beam Epitaxy, Semiconductors... 

Carbohydrates Carbon Cycle Chromatin Structure and Modification Electron Transfer Reactions Energy Flows in Ecology and IN THE Economy Energy Transfer, Intramolecular Ion Transport Across Biological Membranes Lipoprotein/Cholesterol Mp.tabot.tsm Protein Synthesis Thermodynamics... 

This is no longer the case when (iii) motion along the reaction patir occurs on a time scale comparable to other relaxation times of the solute or the solvent, i.e. the system is partially non-relaxed. In this situation dynamic effects have to be taken into account explicitly, such as solvent-assisted intramolecular vibrational energy redistribution (IVR) in the solute, solvent-induced electronic surface hopping, dephasing, solute-solvent energy transfer, dynamic caging, rotational relaxation, or solvent dielectric and momentum relaxation. 

In this chapter we shall first outline the basic concepts of the various mechanisms for energy redistribution, followed by a very brief overview of collisional intennoleciilar energy transfer in chemical reaction systems. The main part of this chapter deals with true intramolecular energy transfer in polyatomic molecules, which is a topic of particular current importance. Stress is placed on basic ideas and concepts. It is not the aim of this chapter to review in detail the vast literature on this topic we refer to some of the key reviews and books [U, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, and 32] and the literature cited therein. These cover a variety of aspects of tire topic and fiirther, more detailed references will be given tliroiighoiit this review. We should mention here the energy transfer processes, which are of fiindamental importance but are beyond the scope of this review, such as electronic energy transfer by mechanisms of the Forster type [33, 34] and related processes. 

Similarly, energy-transfer processes, together with electron transfer and hydrogen abstraction reactions could be induced in poly(organophosphazenes) in an intramolecular way by preparing POPs geminally substituted at the same phosphorus with two different substituent groups. 

Figure 3 Different processes for losing energy from the excited state (1) direct CL (2) molecular dissociation (3) chemical reaction with other species (4) intramolecular energy transfer (5) intermolecular energy transfer (in case of a fluorophore, indirect CL) (6) isomerization (7) physical quenching. (Adapted from Ref. 1.)...

The intramolecular hydrogen atom transfer occurs with lower activation energies in comparison with the intermolecular transfer (see the values of Ee for both types of reactions in Table 6.11). The values of the activation energies of intramolecular radical H-atom abstraction calculated by the IPM method are given in Table 6.15. 

Both RRGM and SLP have been used to compute various transition amplitudes with high efficiency and accuracy. Their applications, which have been reviewed in the literature,56 57 59 include laser-molecule interaction,43 44 99 correlation functions,45 104 absorption and emission spectra,100 103 105-107 intramolecular energy transfer,108-115 vibrational assignment,103 116 117 and reaction dynamics. ... 

In the case of cyclopropyl-diazo-acetate 72 energy transfer reduces the extent of intramolecular in favour of the intermolecular reactions 146). 

It is convenient initially to classify elementary reactions either as energy-transfer-limited or chemical reaction-rate-limited processes. In the former class, the observed rate corresponds to the rate of energy transfer to or from a species either by intermolecular collisions or by radiation, or intramolecular-ly due to energy transfer between different degrees of freedom of a species. All thermally activated unimolecular reactions become energy-transfer-limited at high temperatures and low pressures, because the reactant can receive the necessary activation energy only by intennolecular collisions. 

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