Detailed analysis of the singularities and origin of the ‘extra’ lines in the E.S.R. spectrum of the^·CF₃radical in a polycrystalline matrix

Electron spin resonance study of adsorption stabilization of photolytic trifluoromethyl radicals on zeolites

“…The parallel component of the hyperfine coupling tensor, which was assumed to be almost axial sym- Choosing the exact measurement points with reference to the computer simulated spectrum is somewhat arbitrary at some ±5 G. The line width of the outer peaks (1, 2, 3, and 4) averaged 40 G and of the others (5, 6,7, and 8,) 11 G. The g value was found to be isotropic within experimental limits at 2.0036 ± 0.0003.…”

Applications of EPR and ENDOR Spectrum Simulations in Radiation Research

“…19.7 the experimental spectrum is well accounted for by the exact simulation with α = 17.8°, while the extra lines in the centre part could not be reproduced with second order perturbation theory in Fig. 19.7c, It is nevertheless remarkable that the 19 F hfc tensor of the ĊF 3 radical , could be accurately determined by an analysis of the X-band spectrum in rigid rare gas matrix at an early stage [64,65], in spite of the difficulties to obtain satisfactory simulations based on perturbation theory.…”

“…Some applications involving EPR simulations of radiation induced radicals in low and high molecular fluorinated compounds, including the trifluoromethyl radical, are presented below. Quite large anisotropic splittings due to 19 F hyperfine structure were often observed [64][65][66][67][68][69], both for the neutral radicals formed in the pure systems and in matrices in which ionic radical species were frequently trapped.…”

“…The trifluoromethyl radical, ĊF 3 The EPR spectra of UV-irradiated CF 3 I in rare gas matrices at 4.2 K were interpreted in terms of randomly oriented, non-inverting ĊF 3 radicals with nearly axial hfc tensors in early work [64,65]. The complex shape of the EPR spectrum was attributed to the different orientations of the principal directions of the three 19 F hfc tensors with equal, strongly anisotropic principal values.…”

Molecular and Electronic Structures of the Short-Lived Excited Triplet State of Tropone

“…In the present paper, a quadrupole interaction term is neglected because there is no nuclei with I ≥ 1 in the case of tropone. Second-order perturbation treatments for H eff were carried out for several special cases. − The general solution in an arbitrary coordination system by higher-order perturbation for the high-field case was given by Iwasaki . The present work is also based on the high-field approximation condition: H EZ > H SS ≫ H NZ , H SI .…”