Analysis of the electron transfer mechanism by quantum-chemical methods in titanium-containing model systems.

Yu.V. Stulov, V. G. Kremenetsky, S. A. Kuznetsov. 

ABSTRACT

The electron transfer mechanism in titanium-containing model systems was investigated by quantum-chemical methods. The calculations were performed using the Firefly quantum-chemical package by methods of the density functional theory (DFT). The method of frontier molecular orbitals (FMO) has shown a good applicability for studying electron transfer in the CaTiF₆ + 12CaCl₂ model system. Structures with the high probability of the electron transfer from the cathode to the titanium complex were found. The analysis of systems both with a high-ordered and a low-ordered boundary layer was considered. Such an approach made it possible to reveal the values of the ions boundary shift and compression of the Ti–F bonds, which describe the transition state. It was shown that the structure of the transition state is disordered compared with the initial structures. The structure of transition state corresponds to the actual state of the boundary layer near the electrode surface. Using the FMO method made it possible with a small amount of computer time to determine the structure of the transition state of the TiF₆^2- complex near the electrode surface. The calculated activation energy of the electron transfer was in a good agreement with experimentally determined value.

KEY WORDS:

quantum-chemical calculations, density functional theory, electron transfer, model systems, frontier orbitals, transition state.

DOI: 10.31857/S0235010620060122