Pyramidal geometry around the radical-center carbon atom of some 2-norbornyl-type radicals as studied by electron spin resonance

1973 ◽  
Vol 95 (10) ◽  
pp. 3220-3228 ◽  
Author(s):  
Takashi. Kawamura ◽  
Tohoru. Koyama ◽  
Teijiro. Yonezawa
1974 ◽  
Vol 52 (21) ◽  
pp. 3645-3650 ◽  
Author(s):  
Frederick Peter Sargent ◽  
Edward Michael Gardy

The radicals produced during γ radiolysis of methanol, ethanol, 1-propanol, 2-propanol, and t-butanol have been trapped by reaction with 2-nitroso-2-methylpropane (t-nitrosobutane) to give nitroxides which are detected by e.s.r.[Formula: see text]All the alcohols gave alkoxy radicals and, with the exception of t-butanol, radicals derived by the loss of an H atom from the carbon atom adjacent to the OH group. Methyl radicals were detected in t-butanol.


2020 ◽  
Vol 44 (7-8) ◽  
pp. 460-470
Author(s):  
Bhanu Priya ◽  
Abhishek Kumar ◽  
Neeraj Sharma

New oxidovanadium(IV) complexes of composition [VO(AcSHA)2] 1 and [VO(acac)(AcSHA)] 2 are synthesized by reactions of VOSO4.5H2O and [VO(acac)2] with acetylsalicylhydroxamic acid AcSH2A (C6H4(OH)(CONHOCOCH3)) in a 1:2 molar ratio in absolute ethanol. The compounds are characterized by the Fourier-transform infrared spectroscopy, ultraviolet–visible spectroscopy, electron spin resonance, and mass spectrometry along with elemental analyses, molar conductivity, and magnetic moment measurements. The infrared spectra of the complexes suggest bonding through carbonyl and phenolic oxygen atoms (O,O coordination). The magnetic moment, electron spin resonance, and mass spectra of the complexes indicate that both exist as monomers, and a distorted square pyramidal geometry around vanadium is proposed. The thermal behavior of the complexes is studied by thermogravimetry and differential thermal analysis techniques under an N2 atmosphere, yielding VO2 as the decomposition product. The in vitro antimicrobial assays against pathogenic Gram-positive bacteria, Gram-negative bacteria, and fungi (minimum inhibitory concentration method) show the appreciable antimicrobial potential relative to the respective standard drugs, tetracycline hydrochloride, and fluconazole.


1996 ◽  
Vol 442 ◽  
Author(s):  
Y. Show ◽  
F. Matsuoka ◽  
S. Ri ◽  
Y. Akiba ◽  
T. Kurosu ◽  
...  

Correlation between defects and electrical conduction in surface conductive layers of CVD diamond films has been studied using electron spin resonance ( ESR ) and two points probe technique methods. The ESR analysis revealed the presence of Pac-center with spin density of 1020 spins/cm3. The Pac-center is composed from two ESR signals: ESR signal from carbon dangling bond with carbon atom neighbors and ESR signal from carbon dangling bond associated with nearest neighbor hole ( hole associated Pac-center ). The hole associated Pac-center is an electrically active defect.


1974 ◽  
Vol 52 (20) ◽  
pp. 3529-3538 ◽  
Author(s):  
Kuang S. Chen ◽  
Jay K. Kochi

The e.s.r. spectra of a variety of alkyl radicals with α-halogen substituents have been examined in solution. The configurations of α-halogen substituted ethyl and β,β,β-trifluoroethyl radicals are correlated with the hyperfine splittings of α-methyl protons and α-trifluoromethyl fluorines, respectively. For an α-fluorine substituent, electronegativity plays an important role in determining the pyramidal configuration of the radical center, whereas size appears to be a more important factor with chlorine and bromine in promoting a less pyramidal configuration at the radical center. Two α-halogen substituents have a disproportionately greater effect than one halogen in influencing the configuration at the radical site. The g-factors of fluoroalkyl radicals are qualitatively analyzed in order to discuss possible mechanisms of β-fluorine hyperfine interactions and the effect of trifluoromethyl substitution on the configuration of the radical site.


Sign in / Sign up

Export Citation Format

Share Document