Influence of the N-oxide group in biradicals of the imidazoline series on the intramolecular spin exchange over systems of conjugated bonds

Abstract

Nitroxyl radicals were synthesized with a rigid system of conjugated bonds, containing both imidazoline and imidazoline oxide, as well as imidazoline and imidazoline oxide radical fragments. The EPR method was used to study the characteristic features of intramolecular electronic spin exchange in nitroxyl biradicals of the imidazoline series with a rigid system of conjugated multiple bonds. It was shown that the introduction of the N-oxide group into the imidazoline radical fragment leads to a considerable increase (tens of times) in the value of the exchange integral, characterizing the electronic spin exchange over the system of conjugated bonds.