STRUCTURAL AND SPECTRAL PROPERTIES OF THE COMPLEX VALINE IN NEUTRAL AND IONIC FORM WITH CATIONS Zn2+, Cd2+ (QUANTUM CHEMICAL STUDY)
Heavy metals are involved in the diverse chemical, physico-chemical and biological processes. They can act as toxicants, i. e. substances, which are large concentrations can lead to disorders or disorders of various vital processes of the body. Studying the mechanisms of accumulation and excretion of heavy metals in living cells must be based on a study of the problems with the metal binding amino acids as a component of proteins. Given that the ability of metal ions to interact with the amino acids depends on the presence in their structure of certain atoms and functional groups, this reaction is characterized by the formation of metal complexes of varying strength. Density functional method (DFT), in the framework of self-consistent field (SCF) approximation B3LYP/DZP and taking into account the amendments to the energy perturbation theory MP2 (Moller-Plesset) calculated the geometric parameters of the equilibrium states of complex valine in the neutral and ionic forms cations zinc (II) and cadmium (II) in the gas phase. The influence conformation valine complexes with metals, zinc (II) and cadmium (II), as well as the ionic and neutral forms on their stability. The energies of bond dissociation Val-Me, Me = Zn2+, Cd2+. A number of valine stability of complexes with cations of zinc and cadmium. For cationic complexes with the anionic form of valine [Val--Me2+]1+ calculated IR spectra revealed that changes the fundamental stretching and deformation vibration frequencies. The regularities of the fringe shift in the IR spectra of the complexes [Val--Zn2+]1+, [Val--Cd2+]1+ in complex combination oscillations.