MACROCYCLE ASYMMETRY INFLUENCE ON THE MOLECULAR STRUCTURE OF NH-TAUTOMERS OF THE FREE BASE CORROLE DERIVATIVES

UDC 535.37+541.65+543.4

  • Kruk Mikalai Mikalaevich − DSc (Physics and Mathematics), Associate Professor, Head of the Department of Physics. Belarusian State Technological University (13a, Sverdlova str., 220006, Minsk, Republic of Belarus). E-mail: m.kruk@belstu.by

  • Klenitsky Dmitry Vikentievich − PhD (Physics and Mathematics), Associate Professor, Assistant Professor, the Department of Physics. Belarusian State Technological University (13a, Sverdlova str., 220006, Minsk, Republic of Belarus). E-mail: klen@belstu.by E-mail: klen@belstu.by

  • Gladkov Lev L’vovich − DSc (Physics and Mathematics), Associate Professor, Professor, the Department of Higher Math. Belarusian State Academy of Communications (8/2, F. Skorina str., 220114, Minsk, Republic of Belarus). E-mail: llglad@tut.by

  • Maes Wouter − PhD (Chemistry), Professor. Hasselt University (B-3590, Diepenbeek, Belgium). E-mail: E-mail: wouter.maes@uhasselt.be

DOI: https://doi.org/10.52065/2520-6141-2022-254-1-38-43

Key words: corrole, NH-tautomers, nonplanar distortions, peripheral substitution.

For citation: Kruk M. M., Klenitsky D. V., Gladkov L. L., Maes W. Macrocycle asymmetry influence on the molecular structure of NH-tautomers of the free base corrole derivatives. Proceedings of BSTU, issue 3, Physics and Mathematics. Informatics, 2022, no. 1 (254), pp. 38–43 (In Russian). DOI: https://doi.org/10.52065/2520-6141-2022-254-1-38-43.

Abstract

Equilibrium molecular conformation of the long-wavelength (Т1) and short-wavelength (T2) NHtautomers of the free base unsubstituted corrole and three derivatives with different architecture of peripheral substitution has been calculated with density functional method. It was found that the С1С19 bond length in the dipyrrole fragment was substantially different for two NH-tautomers. The shortening of the С1С19 bond length in going from the long-wavelength Т1 tautomer to the short-wavelength T1 tautomer was due to increase in the nonplanarity of the dipyrrole fragment, which, it its turn, led to the decrease in the strength of the steric interactions between the substituents in the С2 and С18 positions of the pyrrolic rings. The dihedral angle between the pyrrolenine ring to be protonated and the macrocycle mean plane is reciprocal to the С1С19 bond length for both NH-tautomers. Due to different position of the pyrrolenine ring this dependence is more pronounced for the Т1 tautomer. In case of the Т2 tautomer the pyrrolenine ring deviate from the macrocycle mean plane for the lower angle due to the presence of the intramolecular hydrogen bonding. As a result of such structural differences the macrocycle basicity of the T2 tautomer decreased compared to that of the T1 tautomer. Based on the obtained results it was concluded that asymmetric macrocycle structure provided for the key role of the intramolecular interactions in the dipyrrole fragment for the macrocycle molecular conformation.

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References

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06.12.2021