An electron spin resonance study of the radical cations of some p-dialkoxybenzenes

Formation of radical cations of methoxylated benzenes by reaction with hydroxyl radicals, thallium(2+), silver(2+), and peroxysulfate (SO4.-) in aqueous solution. Optical and conductometric pulse radiolysis and in situ radiolysis electron spin resonance study

“…This assignment is confirmed by the fact that the coupling constants and g factors of the isomers are almost identical with those measured in concentrated sulfuric acid6 or aluminum chloride-nitromethane solvent. 29 ESR spectra were also obtained by in-situ irradiation of N20-saturated 10~3 M TI2SO4 solutions containing 10~4 M of the substrates listed in Table I. In the case of 1,3,5-TMB only very weak lines were observed that could not be unambiguously assigned.…”

Long‐Lived Radical Cations of Monocyclic Arenes at Room Temperature Obtained by NbF5 Acting as an Oxidizing Agent and Counterion Precursor

“…Compounds 1 – 3 have been detected in good yields (ca. 70 %) and survive in solution at 20 °C for days, under an argon atmosphere 2a–c,e,f. Remarkably, the crystalline compound 1 lives at 20 °C for several days and represents a rare example of a radical cation salt of a monocyclic arene isolated at room temperature in the solid state 10.…”

Electron transfer quenching of fluorine substituted aryl alkyl ketones. Fluorine-19 polarization via the triplet mechanism

“…The failure to observe polarization for TFA and its derivatives is understandable considering that the magnitude of the polarization is expected to be proportional to 5ZZ2 and that the hyperfine couplings of 8a, aH°= -5.1 G and ízhp = -4.05 or -3.54 G, are considerably smaller than tip" (+25.8 G). [37][38][39][40][41][42][43][44][45][46][47][48] In addition, the hyperfine anisotropies of radicals usually are substantially smaller than the 19F anisotropies. 57 Among the systems for which nuclear spin polarization via the triplet mechanism has been postulated, the case of TFA and its derivatives is unique because it is the only system for which the signal directions predicted by the radical pair and the triplet mechanism can be compared with experimental results for several different nuclei.…”