In this work, the nutation of the spins of unpaired electrons in the nitroxide biradical of bis‑methano[60]fullerene was experimentally studied. Nutation frequencies were found in a wide range of microwave field power. To interpret the obtained results, numerical calculations of the nutation of biradicals were carried out for a set of parameters of the spin-spin interaction of a pair of unpaired electrons and for different values of the Rabi frequency of the microwave field.
View Article and Find Full Text PDFExperimental confirmation of the manifestations of new spin exchange paradigm in EPR spectra of N nitroxide radical solutions is presented. It was shown that in the region of relatively low concentrations of radicals, the two side components of the spectrum have a mixed shape (the sum of the absorptive line and dispersive line). The dispersion contributions in these two lines have opposite signs.
View Article and Find Full Text PDFIsocyanates play an essential role in modern manufacturing processes, especially in polyurethane production. There are numerous synthesis strategies for isocyanates both under industrial and laboratory conditions, which do not prevent searching for alternative highly efficient synthetic protocols. Here, we report a detailed theoretical investigation of the mechanism of sulfur dioxide-catalyzed rearrangement of phenylnitrile oxide into phenyl isocyanate, which was first reported in 1977.
View Article and Find Full Text PDFPhys Chem Chem Phys
November 2023
The spin decoherence of the scandium bimetal in Sc@C(CHPh) is studied at low temperatures (20-120 K) by the electron spin echo technique. The correlation between the magnetic quantum number of the total spin state of the scandium nuclei and the decay rates is established. For the total spin = 5, a decrease of the phase relaxation time by a factor of two is observed by changing the transition from = -1 to = +1 and = -3 at 120 K.
View Article and Find Full Text PDFSpin exchange during random bimolecular collisions of paramagnetic particles in dilute solutions leads to a surprising effect. Collective modes of motion of the average values of the transverse magnetization components (spin coherences) of subensembles of radicals with different resonant frequencies are formed. The elementary excitations of these modes can be considered as quasiparticles.
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