Development and characterization of novel indigoid chromophores, photoswitches and molecular machinery

Petermayer, Christian Patrick (2019): Development and characterization of novel indigoid chromophores, photoswitches and molecular machinery. Dissertation, LMU München: Fakultät für Chemie und Pharmazie

Abstract

The photochemistry and photophysical properties of hemiindigo based photoswitches and indigo based molecular machines were examined. It could be shown that hemiindigos are a class of virtually unexplored, potent photoswitches supporting high photoisomerization ratios with blue over green to yellow and red light, high thermal bistabilities, good quantum yields and high tolerance of the photoreactions towards solvent polarity changes. The introduction of a chiral acyl or aryl axis on the hemiindigo chromophore at the indoxyl nitrogen was tested with various substitution patterns to explore the influence of electronics and sterics on the photophysical properties, electronic circular dichroism spectra and the motion of the passive chiral axes. Introduction of two chiral axes to the well-known indigo chromophore was carried out. The potential of these molecules as prospective molecular motors and -machines was demonstrated, giving insights into novel photoinduced- and thermal motions, which is crucial for the design of nanomachines and molecular robots. Also, addressability within the biooptical window was achieved, as all photosteps can be driven with low energy, 625 nm LED light, making the application of likewise systems available on biological tissues in vitro and in vivo. Three permanently charged, thermally bistable hemiindigos were synthesized and their photochemical properties in the gas phase and in solution were investigated. Several permanently charged hemiindigo photoswitches were tested in water and their photophysical properties as well as their ability to bind to DNA/RNA was scrutinized. Furthermore, the measurement procedures and automatization of photophysical measurements were improved.

• Dokumententyp: Dissertationen (Dissertation, LMU München)
• Keywords: Hemiindigo, Indigo, Photoswitches, Photophysics, Molecular Machines
• Themengebiete: 500 Naturwissenschaften und Mathematik ; 500 Naturwissenschaften und Mathematik > 540 Chemie
• Fakultäten: Fakultät für Chemie und Pharmazie
• Sprache der Hochschulschrift: Englisch
• Datum der mündlichen Prüfung: 15. November 2019
• 1. Bericht­erstatter:in: Dube, Henry