An EPR and quantum-chemical study of the electronic structure of radical-anions of biologically active derivatives of 5-nitrofuran

The electron-acceptor properties of a number of 5-nitrofuran derivatives containing azomethine, vinylquinoline, and other groups, have been studied, and the parameters of the electronic structure of the radical-anions of these compounds have been established. The radical-anions in solution have been identified from the electronic absorption and EPR spectra. The electronic structure of the radical-anions has been determined from the EPR spectra and the results of quantum-chemical calculations by the INDO method with allowance for the solvation of the nitro-group. The nitro-group is the principal electron-acceptor in the compounds studied. The change in the electron-acceptor properties of the substances studied has been followed from the calculated values of the energies of the lowest unoccupied MO and the nucleophilicity indices c/sub i/*/sup 2/.