Abstract
The cations of compounds with condensed rings containing mutually conjugated “pyridine” and “pyrrole” nitrogen atoms were considered as aromatic cyanines by the Hückel MO method. Calculation demonstrates that these sorts of cations should be thermodynamically stable and aromatic. An increase in the number of methylidyne groups between the heteroatoms leads to a bathochromic shift of the long-wave absorption band, but the magnitude of this shift also depends very much on the molecular geometry.
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Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 202–204, February, 1972.
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Éfros, L.S., Ezhova, L.A., Zakhs, É.R. et al. Aromatic cyanines. Chem Heterocycl Compd 8, 180–182 (1972). https://doi.org/10.1007/BF00472353
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DOI: https://doi.org/10.1007/BF00472353