Physico-Chemical nanomaterials science

Modeling of the electronic structure and composition of metal complexes tungsten adsorbed on the electrode surface under conditions of high-temperature electrochemical synthesis.
Soloviev V.V. 1, Solyanik L.A. 1, Kuznetsova T.Yu 1, Usenko D.V1.
1 Poltava National Technical Yuri Kondratyuk University-36000, Ukraine. 
E-mail: dcc_nl_ne@ukr.net

Quantum-chemical modeling of cation-anion interaction and transfer of charge of tungstate-containing melt is made. On the basis of ab initio analysis of the calculation of impact of the cation composition tungstate-containing melt on structural peculiarities of electrochemical active particles, the differences in the structure at implementation of sequential and simultaneous six-electron transfer are determined. The priority of simultaneous transfer over sequential one for all cationised forms of tungstate-ion is justified. According to the results of calculations of charge by Lowdin on the atoms of 'isolated' tungstate-ion during transfer of 6 electrons in the electrode reaction on 'isolated' tungstate-anion, the W atom is the only center of electronic attack. At the electroreduction of cationised complexes, the electron charge is transferred to the cations (mainly) and to the W atom, indicating the existence of two centers of electronic attack. Comparative analysis of the value of the lifetimes of particles during the relaxation of the transient state into equilibrium at constant number of electrons points out to the priority of simultaneous transfer of charge over sequential one for cationised complexes and let to confirm the previously established optimal composition and the form of electrochemical active particles: {Li4+([WO4]2-}2+, {Mg2+2 [WO4]2-}2+ and {Ca22+[WO4]2-}2+. The results of the calculation of geometric, energy and charge characteristics of the electrochemically active particles of tungstate-containing melts and lifetimes of intermediates make it possible to expand the current understanding of the mechanism of electrode processes, allow to conclude that simultaneous electron transfer may be a conventional step in the electrode reactions, and always be considered as an alternative variant for the analysis of the mechanisms of such processes [1]. 

1.	Soloviev V.V., Chernenko L.O. Visnyk Kharkiv Nat’l Univ // 2005.-4.-P. 71.