Molecular rotors: novel luminescent organic materials. Preparation and photophysical characterization

Abstract

This Final Degree Thesis has been focused on the synthesis and study of optical properties of different 9H-carbazole derivatives to, subsequently, keep working with these organic compounds in technologic applications such as haptic interfaces. To obtain the desired compounds, we have modified the 9H-Carbazole structure to introduce in it a bond which allows it to rotate on itself (this kind of compounds are called molecular rotors), providing it with more rigidity to make the product has rotative properties more sensitives to the viscosity environment and it has also been added some functional groups to allow the molecule to form hydrogen bonding with a protic solvent because our study is based on the study of how the compound changes its photochemical behaviour depending on the viscosity and nature of the environment where they are placed in. Synthetic routes that have been followed are very known reactions and have not been a difficulty to the researching work. The chemical structure of our synthetized compounds has been characterized through different spectroscopy techniques such as 1H-NMR, 13C-NMR, mass spectroscopy and IR that are the most common techniques used in conventional organic chemistry. It has been studied the possible interrelation between the solvent viscosity and the optical properties of the desired compounds as well as the interrelation between the solvent nature and these properties. To perform this study, some instrumental techniques have been used such as absorption and emission spectroscopy. Finally, we have observed that there is an interrelation between the fluorescence activity of the dyes and the viscosity of the environment they are placed in. But when the solvent is protic, that dependence gets lost and it behaves with an anomalous dependence