MODELLING OF RING CURRENTS IN MACROHETEROCYCLIC MOLECULES USING EQUIVALENT ELECTRICAL CIRCUIT
UDC 537.8+541.67
Key words: trans-porphin, ring currents, paratropic and diatropic currents, equivalent electrical circuit.
For citation: Prudnikau M. A., Kruk M. M., Modelling of ring currents in macroheterocyclic molecules using equivalent electrical circuit. Proceedings of BSTU, issue 3, Physics and Mathematics. Informatics, 2022, no. 1 (254), pp. 44–49 (In Russian). DOI: https://doi.org/10.52065/2520-6141-2022-254-1-44-49.
Abstract
By transforming the macroheterocyclic trans-porphin molecule into the corresponding equivalent electrical circuit, the electron density redistribution was estimated by analyzing the distribution of ring currents in pyrrole and pyrrolenine rings. Calculations of global and local diatropic and paratropic ring currents were carried out by compiling and solving a system of linear equations from the integrated values of current densities using the GIMIC method. The values of the main elements of the equivalent electrical circuit, such as the resistances of the internal and external branches and the EMF of induction of separate independent circuits, are found. It was found that the values of the passage of the corresponding ring currents depend not only on the obtained resistances of the corresponding elements of the exogenous/endogenous pathway, but also on those small values of local ring currents, among which paratropic ones are predominant, which in turn indicates insufficient aromaticity of the rings in the trans- molecule. porphine. The flow of a larger ring current through the inner branch of the pyrrolenine ring is explained by its strengthening and simultaneous weakening of exogenous bonds by the paratropic local ring current. It was found that it is paratropic currents (mainly global) that change the most probable paths for the flow of ring currents.
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