Open AccessMethods of Dissociative Electron Capture Spectroscopy and Density Functional Theory for Modeling the Biological Activity of Quinoxalin Derivatives
Author(s) -
Mansaf Tayupov,
R. G. Rakhmeev,
Angelina V. Markova,
Aleksey Safronov
Publication year - 2021
Publication title -
matematičeskaâ fizika i kompʹûternoe modelirovanie
Language(s) - English
Resource type - Journals
eISSN - 2587-6902
pISSN - 2587-6325
DOI - 10.15688/mpcm.jvolsu.2021.2.5
Subject(s) - ion , chemistry , molecule , arrhenius equation , electron affinity (data page) , density functional theory , mass spectrometry , radiolysis , adiabatic process , electron , analytical chemistry (journal) , spectroscopy , computational chemistry , organic chemistry , activation energy , chromatography , physics , thermodynamics , quantum mechanics , aqueous solution
The molecules of 2-methylquinoxalin and 2,3-dimethylquinoxalin were studied by mass spectrometry of negative ions of resonant capture of slow (0-15 eV) electrons. These compounds have antimicrobial, antifungal, bactericidal and preservative properties, and are widely used in medicine and the food industry. The average lifetime of molecular negative ions (NI)relative to electron auto-cleavage is measured experimentally. The most probable structures of fragment ions ([M – H]–, formed during the decay of molecular NI, are revealed. Within the framework of the Arrhenius approximation, the value of the adiabatic electron affinity (EAa) was estimated. It is found that the theoretical values of EAa calculated by the B3LYP/6-31+G(d) method with minimal addition of diffuse functions as the difference between the total energies of the neutral molecule and the radical anion correlate with the values of EAa obtained from the experiment.