ON THE STRUCTURE OF COPPER(II) COORDINATION COMPOUNDS WITH L-HISTIDINE
V. T. Panyushkin1, I. N. Shcherbakov2, V. A. Volynkin1, S. N. Bolotin1, N. N. Bukov1, T. V. Shvydko2, L. Kh. Dzhabrailova3, M. Kh. Shamsutdinova3
1Kuban State University, Krasnodar, Russia
2South Federal University, Rostov-on-Don, Russia
3Chechen State University, Grozny, Russia
Keywords: L-гистидин, ЭПР, DFT, L-histidine, EPR
Abstract
Quantum chemical calculations are performed for the spatial and electron structure of complex compounds of L-histidine and its ionized forms with copper(II) for a variety of compositions within the density functional theory (DFT) using the B3LYP functional and 6-311G(d) basis. The solvent (water) is considered within the PCM approximation. EPR spectroscopy is used to study the equilibrium in the copper(II)-L-histidine system in an aqueous solution at рН 2-11. A comparison between the theoretical calculations and the EPR spectra suggests the following geometry for the coordination environment of the copper(II) ion in the complex compounds: CuHLL - square-planar coordination; CuL2, CuHLL', and CuLL' - distorted square pyramid; and - octahedral environment.
|
