| Abstract: | A study of the nuclear magnetic resonance spectra of six hydrazyl radicals in solution, including α,α′-diphenyl-β-picryl-hydrazyl (DPPH), has been carried out. From the values of the paramagnetic shifts the constants (αH) of hyperfine coupling with the protons were found. For DPPH these have the following values:  On the basis of the analysis of the hyperfine constants a conclusion is drawn concerning the substantial role of σ-electron spin density delocalization in aromatic rings. The geometric structure of radicals investigated is also discussed in the paper. |
