Determination of the average singlet-triplet splitting in biradicals by measurement of the magnetic field dependence of CIDNP [chemically induced dynamic nuclear polarization]

1973 ◽  
Vol 95 (8) ◽  
pp. 2735-2736 ◽  
Author(s):  
G. L. Closs ◽  
C. E. Doubleday
Keyword(s):  
Magnetic Field ◽  
Field Dependence ◽  
Dynamic Nuclear Polarization ◽  
Magnetic Field Dependence ◽  
Nuclear Polarization ◽  
Triplet Splitting ◽  
Chemically Induced ◽  
The Magnetic Field

Chemisch induzierte Kernpolarisation von Phenylhalogeniden bei der Photolyse von Aroylperoxiden

1969 ◽  
Vol 24 (11) ◽  
pp. 1771-1778 ◽  
Author(s):  
M. Lehnig ◽  
H. Fischer
Keyword(s):  
Magnetic Field ◽  
Field Dependence ◽  
Dynamic Nuclear Polarization ◽  
Nmr Spectra ◽  
Magnetic Field Dependence ◽  
Nuclear Polarization ◽  
Radical Reactions ◽  
Chemically Induced ◽  
Polarization Mechanism ◽  
The Magnetic Field

Abstract By a flow technique chemically induced nuclear polarization is observed in the NMR-spectra of phenylhalides formed during photolysis of aroylperoxides in solution. The main features of the polarization are quantitatively explained by dynamic nuclear polarization (CIDNP) of protons in the intermediate phenyl radicals. Some details however indicate that a second polarization mechanism is also present. This mechanism leads to a multiplet-effect type polarization and operates presumably during bond fromation in the radical reactions. Some results on the magnetic field dependence of the nuclear polarizations are given.

Chemically Induced Dynamic Nuclear Polarization. X. On Effects of Nuclear Relaxation and the Magnetic Field Dependence

1972 ◽  
Vol 27 (8-9) ◽  
pp. 1300-1307 ◽  
Author(s):  
M. Lehnig ◽  
H Fischer
Keyword(s):  
Magnetic Field ◽  
Field Dependence ◽  
Magnetic Field Dependence ◽  
Nuclear Polarization ◽  
Radical Pair ◽  
Reaction Products ◽  
Theory Analysis ◽  
Alkyl Radicals ◽  
Chemically Induced ◽  
The Magnetic Field

Abstract The magnetic field dependence of CIDNP is presented for two reaction products of independently generated alkyl radicals. It is shown that nuclear spin relaxation of the products influences the intensity distributions within multiplets, and how this relaxation can be included in the calculation of CIDNP effects from the radical pair theory. Analysis of the experimental results supports the recent view that CIDNP is created in pairs of radicals which undergo many diffusive displacements before reencounter.

Sign in / Sign up

Export Citation Format

Share Document