Transfer of electronic energy

Vectorial transfer of electronic energy in rod-like ruthenium-osmium complexes with bis-2,2, 2"-terpyridine ligands 97CC333. 

Simpson WT, Peterson DL (1957) Coupling strength for resonance force transfer of electronic energy in Van der Waals solids. J Chem Phys 26 588-593... 

Fluorescence energy transfer is the transfer of electronic energy from a molecule in an excited state (donor) to another molecule (acceptor). The efficiency of this process is dependent on the distance between the donor and the acceptor. The fluorescence energy transfer process may or may not lead to emission of fluorescence by the acceptor. The transfer is due to... 

The molecular ion will be of low symmetry and have an odd electron. It will have as many low-lying excited electronic states as necessary to form essentially a continuum. Radiationless transitions then will result in transfer of electronic energy into vibrational energy at times comparable to the periods of nuclear vibrations. 

Physical quenching of Hg-resonance radiation by added gases may occur hv a number of mechanisms (i) transfer of electronic energy to the addeo gas (E - E transfer), (ii) energy transfer in the vibrational modes (E V transfer),... 

There are, however, other ways in which excited-state decay can be accelerated by other species, which cannot be classified as reversible chemical reactions. Such processes can be represented generally by (1.12), where a star denotes electronic excitation. The excited state of A is said to be quenched by B. If B is converted into an electronically excited state (B ) during the process, an overall transfer of electronic energy takes place between the excited and unexcited partners of the interaction. 

We shall begin with a closer look at electronic excitation, some aspects of which were discussed in Section 9-9. Because transfer of electronic energy from one molecule to another is a basic process in photochemistry, we will discuss energy transfer also before giving an overview of representative photochemical reactions. The closely related phenomena of chemiluminescence and bioluminescence then will be described. Finally, there will be a discussion of several important applications of photochemistry. 

Gill and Laidler (33), however, concluded that the 32a+ state would be the most probable one reached. The crux of their argument is that the potential energy surfaces for the interaction between oxygen and mercury indicate that the least transfer of electronic energy into other forms would occur for this transition. To account for the effects of foreign gases, it was then necessary to conclude that their major role was on reaction (19) and that the order of effectiveness was... 

Several phenomena may occur when 63P1 mercury atoms encounter other molecules. The simplest of these would be the transfer of electronic energy from one atom to another... 

The transfer of electronic energy from 6 3Pj mercury atoms to di- and polyatomic molecules by steps analogous to (28) is known to occur3. This may occur wholly or in part by the processes... 

A more common process than those illustrated in Equations 6.80-6.82 is the transfer of electronic energy of the excited state S to an acceptor A (Equation 6.83). 

The transfer of electronic energy (and excitation) between two different molecules (intermolecular energy transfer pathway iv of Fig. 1) or between two different electronic states (intramolecular energy transfer pathway v) plays a central role in photochemistry. The equivalent processes involving electrons, in which charge is transferred to a different molecule, or is moved in position in one molecule, may also be promoted photochemically. These processes are explored in the present section. 

A plug/socket system that deals with the transfer of electronic energy is illustrated in Fig. 7 [57]. The absorption and fluorescence spectra of a CH2CI2 solution containing equal amounts of binaphthocrown ether 4 and amine 5 indicate... 

Spin conservation rule (Wigner rule) Upon transfer of electronic energy between an excited atom or molecular entity and other atom or molecular entity in its ground or excited state, the overall spin angular momentum of the system, a vector quantity, should not change. 

C. Intermolecular Electronic Energy Transfer Quenching of one excited-state species may result in transfer of electronic energy to the quenching species. Intermolecular energy transfer has become an important technique in photochemistry because it often permits the selective population or depopulation of one specific excited-state species. 

Another alternative for the decay of excited states is the transfer of electronic energy to suitable acceptors. Such a process can be represented by... 

We now embark upon one of the more difficult of the concepts to be presented. We have already presented the types of "poles" possible without defining their nature. There are a variety of electronic transitions based upon the spacial configuration of the electrons involved. These interpolar interactions are responsible for transfer of electronic energy from site to site in the lattice. As shown below, there are "dipole-dipole" interactions, i.e.- "dd" as weU as "dipole-quadrupole" interactions, i.e.-"dq". There are even "quadrupole-quadrupole transitions. I.e. "qq". 

Collision-induced rotational relaxation is very much more efficient when resonant transfer of electronic energy is possible than when it is not possible. The cross-sections reported for rotational energy transfer in collisions of Bjy and benzene molecules, and in collisions of... 

Electronic Energy Transfer. Represented generally, this simply refers to the transfer of electronic energy from an excited electronic state of a donor molecule O to an acceptor A, through... 

The transfer of electronic energy into rovibronic energy has much larger cross sections than the electronic to translational energy ( E - T) transfer [1009]. These processes are of crucial importance in photochemical reactions of larger molecules and detailed studies with time-resolved laser spectroscopy have brought much more insight into many biochemical processes [1010-1012],... 

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