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Electron nuclear dynamics format

Dynamics. Cluster dynamics constitutes a rich held, which focused on nuclear dynamics on the time scale of nuclear motion—for example, dissociahon dynamics [181], transihon state spectroscopy [177, 181, 182], and vibrahonal energy redistribuhon [182]. Recent developments pertained to cluster electron dynamics [183], which involved electron-hole coherence of Wannier excitons and exciton wavepacket dynamics in semiconductor clusters and quantum dots [183], ultrafast electron-surface scattering in metallic clusters [184], and the dissipahon of plasmons into compression nuclear modes in metal clusters [185]. Another interesting facet of electron dynamics focused on nanoplasma formation and response in extremely highly ionized molecular clusters coupled to an... [Pg.270]

Further evidence for the formation of alkene radical cations derives from the work of Giese, Rist, and coworkers who observed a chemically induced dynamic nuclear polarization (CIDNP) effect on the dihydrofuran 6 arising from fragmentation of radical 5 and electron transfer from the benzoyl radical within the solvent cage (Scheme 6) [67]. [Pg.19]

Formation of specific complexes in the excited states ( exciplexes )f 35 52 85) Exciplexes are complexes not present in the ground state that form due to the extensive redistribution of electron density that occurs upon excitation. Among exciplexes, there may be some whose formation does not require substantial nuclear rearrangements and thus occurs rather rapidly even at 77 K. The formation of exciplexes is accompanied by a spectral shift to longer wavelengths. It is postulated that the fluorescence from tryptophan in proteins in a variety of cases is fluorescence from tryptophan exciplexes)35 85) In studies of the effects of environmental dynamics on the spectra, the exciplexes may be considered as individual fluorophores. [Pg.86]

The photochemistry of benzaldehyde (90% 13C=0), 519, deoxybenzoin (99%) 13C=0), 521, and / -chloro benzoin (99% 13C=0), 522, in cyclohexane-Dn solution has been studied633 by spectroscopic techniques, such as XH chemically induced dynamic nuclear634 or electron polarization635 (CIDNP/CIDEP) or dynamic nuclear polarization636 (DNP). In all these cases the formation of benzaldehyde-D with emissive 13C=0 polarization has been observed and the results rationalized by intermolecular hydrogen (deuterium) abstraction by the photoexcited ketones from the solvent molecules and by reactions of cage-escaped radicals (equations 303-308), Benzoin, 520, is formed also. [Pg.1075]

A quantum mechanical theory is in principle needed to describe molecular phenomena in both few-atom and many-atom systems. In some cases a single electronic state is involved, and it is possible to gain valuable insight using only classical molecular dynamics, which can be relatively easy to apply even for a system of many atoms. A quantum mechanical description of molecular phenomena is however clearly needed for electronic states, insofar these have pronounced wavemechanical properties. The need for a quantum description of nuclear motions in molecular dynamics is less apparent, but it is required in some important situations. If we consider a generic interaction between two species A(a) and B(j3) leading to formation of two others, C(7) and D(6), all of them in the specified quantum states, so that... [Pg.140]

A more profound knowledge of the photolytic processes of a drug substance under UV-VIS photon exposure can be obtained utilizing this method of experimental photochemistry. The irradiation of many drug substances having photosensitizing properties results in the formation of free radicals as part of their primary photochemical processes (17). The formation of these radicals can be detected and monitored by means of electron spin resonance (ESR) or nuclear resonance spectrometry, especially utilizing the chemically induced dynamic nuclear polarization technique (8). [Pg.300]


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See also in sourсe #XX -- [ Pg.737 ]




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