| Popis: |
In this work we have carried out empirical Huckel and semiempirical INDO/S MO calculations on a few tetraazaannulene compounds and obtained an estimate for the redox potentials of 17,21-dichloro-5,7,12,14-tetramethyl-dibenzo[ b,i ][1,4,8,11]tetraaza[14]annulene. Our calculated value of 0.79 V for the oxidation potential is very close to the experimental value of 0.73 V. For the still unknown reduction potential, we have obtained a value close to −2.2 V. We are also interested in the UV–visible spectra of some of these compounds. We have obtained the absorption electronic spectra of the free ligands using the INDO/S technique as parametrized by Zerner and coworkers. As expected, the calculated spectra is associated with π→π ∗ excitations: the strong absorptions at 344, 274, 250, and 224 nm of the observed spectrum are all very well described. |
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