Non-symmetrical diarylethenes with turn-on mode fluorescence & Photochromic surface ligands for gold nanoparticles and 2D superconductors

Abstract

Within the scope of this thesis the three distinct projects “FluoroChrom”, “PlasmoChrom” and “SuperMol” were explored. The lion’s share of this work were the syntheses of novel photochromic compounds. In this work the syntheses of 33 novel photochromic compounds were presented. This set of compounds is comprised of 16 benzo[b]thiophene derived non-symmetrical diarylethenes and 12 benzo[b]thiophene-1,1-dioxide derived non-symmetrical diarylethenes, all with varying substitutional patterns and a electronically divers set of substituents. The combination of FRIEDEL-CRAFTS acylations, MANNICH-methylenations, MUKAIYAMA-MICHAEL and MCMURRY reactions provided a solid toolbox for use in further studies of non-symmetrical diarylethenes. In the process of developing efficient routes to these diverse compounds a straightforward and generally applicable synthetic methodology towards four bromo-2-ethylbenzo[b]thiophenes was established. The 28 synthesized DAEs of “FluoroChrom” were subjected to irradiation experiments in dilute concentrations and their photochemical and photophysical characteristics were examined. The photochemical and photophysical properties are clearly and drastically dependent on the position and electronic nature of the appended substituent. Furthermore, the syntheses of two non-symmetrical thienyl-derived DAEs bearing sulphur peripheries and three new bifunctional linkers are reported in chapter 4 “PlasmoChrom”. In chapter 5 “SuperMol”, two non-symmetrical thienyl-derived DAEs bearing either an olefin or triethoxysilyl group and one non-symmetrical azobenzene are described. Additionally, a large set of potential photochromic compounds for use in photoswitchable superconductors were explored in silico.