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Radical pair mechanism, chemically induced dynamic electron polarization

CIDEP (Chemically Induced Dynamic Electron Polarization) Non-Boltzmann electron spin state population produced in thermal or photochemical reactions, either from a combination of radical pairs (called radical-pair mechanism), or directly from the triplet state (called triplet mechanism), and detected by ESR spectroscope... [Pg.305]

In 1963, Fessenden and Schuler [1] found during irradiation of liquid methane (CFLt and CD4) at 98 K with 2.8 MeV electron that the low-field line for both hydrogen and deuterium atoms appeared inverted (emissive signals) and that the central deuterium atom line was very weak. Although the cause of such anomalous ESR spectra was not clear at that time, similar anomalous signals have been observed in many reactions and have been called " Chemically Induced Dynamic Electron Polarization (CIDEP). CIDEP should be due to non-equilibrium electron spin state population in radicals and could also be explained later by the radical pair mechanism as CIDNP. [Pg.47]

Such anomalous NMR spectra as observed in the above reactions have been called Chemically Induced Dynamic Nuclear Polarization (CIDNP) . CINDP should be due to nonequilibrium nuclear spin state population in reaction products. At first, the mechanism of CIDNP was tried to be explained by the electron-nuclear cross relaxation in free radicals in a similar way to the Overhauser effect [4b, 5b]. In 1969, however, the group of Closs and Trifunac [6] and that of Kaptain and Oosterhoff [7] showed independently that all published CIDNP spectra were successfully explained by the radical pair mechanism. CIDEP could also be explained by the radical pair mechanism as CIDNP. In this and next chapters, we will see how CIDNP and CIDEP can be explained by the radical pair mechanism, respectively. [Pg.38]


See other pages where Radical pair mechanism, chemically induced dynamic electron polarization is mentioned: [Pg.72]    [Pg.476]    [Pg.156]    [Pg.42]    [Pg.25]    [Pg.261]    [Pg.21]    [Pg.261]    [Pg.885]    [Pg.581]    [Pg.21]    [Pg.1590]   
See also in sourсe #XX -- [ Pg.101 ]




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Chemical Induced Dynamic

Chemical Induced Dynamic Electron Polarization,

Chemical dynamics

Chemical mechanisms

Chemical-mechanical

Chemically induced

Chemically induced dynamic

Chemically induced dynamic electron

Chemically induced dynamic electron polarization

Chemically induced dynamic radical pair mechanism

Chemically polar

Dynamic mechanisms

Dynamic polarization

Dynamical mechanical

Electron chemically induced

Electron chemically induced polarization

Electron dynamics

Electron mechanisms

Electron polar mechanism

Electron polarization

Electron radicals

Electron-radical mechanism

Electronic chemicals

Induced polarization

Mechanical polarization

Mechanically induced chemical

Pairing mechanism

Polar mechanisms

Polar radicals

Polarity induced

Polarization chemical

Polarization electronic

Polarization mechanism

Polarization radical

Radical mechanism

Radical pair dynamics

Radical pair mechanism

Radical pair mechanism polarization

Radical pair mechanism, chemically induced

Radicals polarity

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