| Popis: |
The electrochemical oxidation of various open-chain and cyclic amidrazones in acetonitrile was investigated by cyclic voltammetry. The oxidation was found reversible for both N-disubstituted open-chain amidrazones and all cyclic compounds with the exception of triazole derivatives that could not be oxidized. Microcoulometry revealed an extrapolated charge consumption of one electron per molecule. The experimentally obtained oxidation potentials correlate well with the reaction energy of oxidation calculated from density function theory (DFT) that clearly supports the hypothesis of a persistent radical formation. The total atomic spin density of radical cations was calculated and permits to make a statement about the localization of radical formation. The synthesis of (E)-2-(methylphenyl)hydrazono-N-phenyl-2-piperidin-1-ylacetamide 7 representing open-chain α-carbonyl substituted N-alkyl, aryl-amidrazones and the synthesis of 6-aminosubstituted 2,3,4,5-tetrahydro-1,2,4-triazin-5-ones, a new class of amidrazones, are described. |
