Electronic Spectra and Structures of Organic π-Systems. IV. Electronic Spectra of Nitropyrroles

The electronic spectra of 2-nitropyrrole and 3-nitropyrrole have been measured in various solvents and compared with the values calculated by the variable integrals method II. Agreement between the observed and the calculated transition energies is satisfactory. From eigenvectors of both nitropyrroles, the localization of molecular orbitals to the moiety of molecule has been discussed. The π-electon densities and π-bond orders of both molecules have also been calculated.