Uloga veličine i oblika molekulskih propelera u njihovoj dinamičnoj stabilnosti u modelu kvantnog Braunovog rotatora

Abstract

The subject of this doctoral dissertation research is the rotational dynamics of molecules of a specific shape, the so-called molecular propellers. The main task of the dissertation is to consider the influence of the size and shape of the mentioned molecules upon their dynamic stability. The model used is based on the application of the theory of open quantum systems and the master equations of Caldeira and Leget, as a quantum model of Brownian motion. The size of molecular propellers was introduced into the model through the dependence of the moment of inertia and the strength of the interaction with the environment on the number of blades. Dynamic stability is examined by analysis of standard deviations of the angle and momentum and by the method of quantum first time passage. The obtained results indicate a strict and complex dependence of dynamic stability on the number of blades, temperature and strength of interaction with the environment. The results also show that to achieve the desired level of dynamic stability, it is not possible to apply simple rules but a combination of different stability criteria and a procedure similar to engineering optimization is necessary.