The NMR spectra of 1-vinylimidazole, transformed by the additives of paramagnetic complexes of manganese, cobalt, nickel and copper chlorides with this azole, have been studied. It is shown that the coordination atom in a solution has octahedral surrounding, four ligand molecules being located in the equatorial position. The nature of hyperfne coupling in the above complexes is evaluated by comparison of the experimental constants of hyperfne coupling with theoretically calculated spin densities of unpaired electrons on s-orbitals in the vinylpyrrole radical, which is isostructural to the molecule of 1-vinylimidazole. It is found that in the complexes of cobalt, nickel and copper, the molecules of 1-vinylimidazole are coordinated to the central ion by the pyridine N-3 atom. Therefore, paramagnetic shifts observed for the specifed complexes are mainly caused by unpaired spin density delocalized in -system of the ligand molecule. Notably, in the paramagnetic complex of manganese, hyperfne coupling is transferred both through  - and   -systems of the 1-vinylimidazole molecule. Localization of the unpaired spin density is due to the fact that molecules of this azole can also be coordinated by the pyrrole N-1 atom at a certain range of temperatures. In its turn, the specifed possibility is explained by non-planar structure of a heterocycle in 1-vinylimidazole. 

Vladimir Voronov's research interests are related to solving problems of molecular spectroscopy and physico-organic chemistry by methods of nuclear magnetic resonance and quantum chemistry. In addition, for the last twenty years or so, his research interests have included scientific and methodological issues related to cognitive barriers of university students. He is the author of more than three hundred publications in periodicals, including more than thirty books. He received a number of awards established by the Russian Academy of Natural Sciences, including the Gold Medal "For innovative work in the field of higher education". Member of the American Chemical Society.