Showing papers by "Dante Macciantelli published in 2000"
TL;DR: In this paper, the reduction of a number of phosphoryl and thiophosphoryl formates, monothio-formates and dithioformates has been studied by means of cyclic voltammetry and EPR spectroscopy.
Abstract: The reduction of a number of phosphoryl- and thiophosphoryl formates, monothioformates and dithioformates has been studied by means of cyclic voltammetry and EPR spectroscopy. The reduction potentials of all dithioformates are close to −1 V vs. SCE, and increase for S-alkyl monothioformates and even more for O-alkyl monothioformates. The radical anions of the compounds bearing the thiocarbonyl function have been characterised by means of EPR spectroscopy, whereas those of the compounds having the carbonyl function underwent decomposition before detection. Reduction at higher potentials led in most cases to the detection of paramagnetic dianions derived from fragmentation of the initially formed radical anions.
18 citations
TL;DR: The identification of the species observed by EPR spectroscopy in the SmI(2)-promoted coupling of N-(N', N'-dialkylaminoalkyl)benzotriazoles as substituted benzyl radicals is disputed on the basis of results obtained studying the model radical derived from tribenzylamine.
6 citations
TL;DR: The photochromic nitrone of the chromene series was synthesized and ESR studies proved its ability to act as a spin trapping agent as mentioned in this paper, and the rate constant for ring closure, i.e., the conversion of the latter isomer into the former upon ceasing optical excitation, was measured as 7 × 10−3 s−1 at 20°C.
Abstract: The title compound, a nitrone of the chromene series exhibiting photochromic properties, was synthesized and ESR studies proved its ability to act as a spin trapping agent. Although in general the aminoxyls formed in the trapping process did not exhibit any evidence of opening of the heterocyclic ring, both the closed and open forms have been observed for the spin adduct of the methyl radical. The rate constant for ring closure, i.e. the conversion of the latter isomer into the former upon ceasing optical excitation, was measured as 7 × 10−3 s−1 at 20°C. The new photochromic nitrone did not exhibit a significant stabilizing effect towards Corn Yellow, a typical photochromic compound, but its action was synergistic to that of popular commercial additives. Copyright © 2000 John Wiley & Sons, Ltd.
3 citations
TL;DR: An α-terthiophene/cellulose triacetate film system exposed to γ-rays and electron beam shows two new bands in the visible region of the spectrum.
3 citations