1 research outputs found
Nature of Electrogenerated Intermediates in Nitro-Substituted Nor-β-lapachones: The Structure of Radical Species during Successive Electron Transfer in Multiredox Centers
Electrochemical,
spectroelectrochemical, and theoretical studies
of the reduction reactions in nor-β-lapachone derivatives including
a nitro redox center showed that reduction of the compounds involves
the formation of several radical intermediates, including a biradical
dianion resultant from the separate reduction of the quinone and nitro
groups in the molecules. Theoretical descriptions of the corresponding
Fukui functions <i>f</i><sub>αα</sub><sup>+</sup> and <i>f</i><sub>ββ</sub><sup>+</sup>(<b>r</b>)
and LUMO densities considering finite differences and frozen core
approximations for describing the changes in electron and spin densities
of the system allowed us to confirm these results. A description of
the potential relationship with the obtained results and biological
activity selectivity indexes suggests that both the formation of stable
biradical dianion species and the stability of the semiquinone intermediates
during further reduction are determining factors in the description
of their biological activity