Kovalenko O. Physical processes in spiropyrans as elements of moletronics

The thesis is devoted to the establishment of regularities that determine the relationship between the molecular energy structure and the formation of transformation mechanisms in theSpiropyran-Merocyanine system.Also it aims to study possibilities and conditions for building molecular devices based on the spiropyran molecule. It has been shown that changes of (in) configurations during the transformation in the spiropyran-merocyanine system can be used to implement a memory cell with spectroscopic differentiation. It has been proposed to use a Cl as a substitute in the indoline moietythat leads to the decreasing of the energy barrier by 36 % in the direct conversion and by 42 % in the reverse conversion. The mechanism of the Sp-Mc conversion (switching) without irradiation influence has been obtained and investigated. It can be achieved by protonation of the spiropyran molecule. It has been found that proton transfer has noaffect on the switching rate. Rotational processes of McH+ conformers are the rate determining steps. It has been found out that the overall reaction is exothermic, that is opposite to the case of the non-protonated system, where it was endothermic. It has been demonstrated that a linear increasing of the external electric field strengths decreases the energy barrier during proton transfer.