Control of supramolecular phenomena via molecular motors

PhD ceremony: Ms. M.G.M. Jongejan, 16.15 uur, Academiegebouw, Broerstraat 5, Groningen

Thesis: Control of supramolecular phenomena via molecular motors

Promotor(s) prof. B.L. Feringa

Faculty: Mathematics and Natural Sciences

The research concentrated on the amplification of chirality. This means that a chiral molecule (which has a mirror image) influences several surrounding non chiral molecules in such a way as to generate chirality on a larger scale. In this research the chiral molecule used was a molecular motor. Upon adding these molecules to a simple liquid crystalline molecule a fingerprint texture can be observed through a microscope. Through irradiation with UV light a rotation of the phase can be observed. We have tested a computer model which predicts this behavior and that this is only reversible for open systems.

A single molecular motor which is attached to a polymer chain also generates the previously mentioned fingerprint texture. Upon UV irradiation the pattern changes. The system can be returned to the starting position using visible light. When these polymer chains are deposited on a surface equidistant small rings are observed. These rings are really small (nm schaal) and form a highly ordered pattern over large areas (100 x 100 μm).

The first water soluble molecular motor was synthesized. These generate micelles (soap bubbles) in water. Lower concentrations are needed of a molecular motor which has been irradiated with UV light to form micelles than if UV irradiation has not been applied.