scholarly journals ELECTRON SPIN RESONANCE STUDIES ON THE CYCLOPENTADIENYL RADICALS. ON THE13C HYPERFINE COUPLING CONSTANT AND SUBSTITUENT EFFECTS BY DEUTERIUM AND ALKYL GROUPS

1979 ◽  
Vol 8 (8) ◽  
pp. 973-976 ◽  
Author(s):  
Mitsuo Kira ◽  
Mieko Watanabe ◽  
Hideki Sakurai
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
Hyperfine Coupling ◽  
Substituent Effects ◽  
Hyperfine Coupling Constant ◽  
Coupling Constant ◽  
Alkyl Groups ◽  
Spin Resonance

Electron Spin Resonance Spectrum of the tert-Butylperoxy Radical, B16O17O•

1972 ◽  
Vol 50 (12) ◽  
pp. 1981-1983 ◽  
Author(s):  
J. A. Howard
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin Resonance Spectrum ◽  
Electron Spin ◽  
Hyperfine Coupling ◽  
Resonance Spectrum ◽  
Hyperfine Coupling Constant ◽  
Coupling Constant ◽  
Tert Butyl ◽  
Spin Resonance ◽  
Butyl Peroxide

A tert-butylperoxy radical specifically labelled with 17O on the terminal oxygen has been prepared by photolysis of di-tert-butyl peroxide in perdeuterocyclopentane containing 17O enriched oxygen. The value of the 17O hyperfine coupling constant is 23.45 G.

scholarly journals The Coordination Chemistry of Phosphoryl Compounds Containing the -N(CH3)2 Group, XII.

1973 ◽  
Vol 28 (3-4) ◽  
pp. 104-106 ◽  
Author(s):  
M.W.G. De Bolster ◽  
B. Nieuwenhuijse ◽  
J. Reedijk
Keyword(s):  
Electron Spin Resonance ◽  
Metal Ion ◽  
Room Temperature ◽  
Esr Spectroscopy ◽  
Hyperfine Coupling ◽  
Hyperfine Coupling Constant ◽  
Zero Field ◽  
Coupling Constant ◽  
Spin Resonance ◽  
Temperature Electron

Room temperature electron spin resonance powder spectra have been recorded for some compounds of the type Mn(ligand)p(anion)2 with hexamethylphosphoramide and nonamethylimidodiphosphoramide as ligands (p = 1 - 4) and BF-4, NO-3, Cl-, Br-, I- and NCS-as anions.The values for the zero-field parameters, D and λ, have been determined and are compared with literature data. It is shown that ESR spectroscopy can be very helpful in elucidating the structures of manganese(II) complexes.The high values for the hyperfine coupling constant of the solvates suggest that in these complexes the bonding between the ligands and the metal ion is essentially ionic.

Electron Spin Resonance Linewidth Studies of Vanadyl Tetraphenylporphyrin

1993 ◽  
Vol 58 (6) ◽  
pp. 1294-1298
Author(s):  
Ali H. Al-Mowali ◽  
Alhan D. Girgees
Keyword(s):  
Electron Spin Resonance ◽  
Unpaired Electron ◽  
Hyperfine Coupling ◽  
Hyperfine Coupling Constant ◽  
Esr Spectra ◽  
Coupling Constant ◽  
Electron Spin Resonance Linewidth ◽  
Isotropic Hyperfine Coupling ◽  
Spin Resonance ◽  
Line Widths

The linewidths of the hyperfine components of the ESR spectra of vanadyl tetraphenylporphyrin in liquid toluene have been measured as a function of temperature and analyzed in detail. This has allowed the separate contributions to the observed ESR line widths from spin rotational, g tensor anisotropy, hyperfine anisotropy and unresolved nitrogen hyperfine coupling to be evaluated. These results have been used to estimate the size of the nitrogen isotropic hyperfine coupling constant and thus the extent of delocalization of the unpaired electron onto the nitrogen atoms.

Electron Spin Resonance Super-Hyperfine Splitting Study of Polycrystalline Niobocene and Vanadocene Dichlorides

1996 ◽  
Vol 61 (12) ◽  
pp. 1767-1772 ◽  
Author(s):  
Jana Holubová ◽  
Zdeněk Černošek ◽  
Ivan Pavlík
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
Unpaired Electron ◽  
Hyperfine Splitting ◽  
Hyperfine Coupling Constant ◽  
Esr Spectra ◽  
Coupling Constant ◽  
Average Value ◽  
Spin Resonance ◽  
Vanadocene Dichloride

The electron spin resonance (ESR) spectra of niobocene and vanadocene dichlorides were studied on the title compounds prepared as magnetically diluted species in polycrystalline form. The resolved super-hyperfine splitting of anisotropic ESR spectra of both studied compounds was firstly observed. Computer simulation confirmed that this super-hyperfine splitting is due to interaction of unpaired electron with nuclear spin of two chlorine ligands. Average value of super-hyperfine coupling constant is 13.3 MHz for niobocene dichloride. For vanadocene dichloride, it is estimated to be in the range of 6-10 MHz. It corresponds approximately to 10% delocalization of metal unpaired electron spin density onto chlorine ligands in case of niobocene dichloride and to 4-7% delocalization in case of vanadocene dichloride.

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