Elucidation of chemical phenomena by means of computational chemistry

Abstract

The goal of this PhD work was the application of tools of computational chemistry in various research areas of chemistry. The first chapter deals with the mechanism of the unusual spontaneous cyclization of Acridin-9-ylmethyl thioureas observed during the attempted synthesis of new spirocompounds based on the acridine skeleton. The reaction path simulations were performed using ab initio quantum chemistry methods. The new reaction mechanism was suggested, in which the thione tautomer of thiourea intermediate plays a crucial role and determines the course of the whole reaction. In the second part, structural aspects of the modified DNA double strand were investigated by means of molecular dynamics. Simulations shed light on the behaviour of the deformed double strand upon irradiation. The observed phenomena can be explained in terms of local deformations caused by two CPD units, which cause the preference of the electron transfer in one direction. The goal of this theoretical study was to attempt to find answers to particular questions emerging during the practical experiments. In this regard, it was successful. I see it as a nice example of combining the experimental work with theoretical models in pursuing the common objective. As the science advances, more sophisticated problems are emerging. To address these questions, more complex approaches are required. And in my opinion, the computational chemistry has already established its firm and undisputable position as a powerful tool in the modern era of multi-disciplinary projects.