Hemithioindigo-based Photoswitchable Self- Complementary Hydrogen Bond Arrays
Abstract
Hydrogen bonded materials are slowly conquering grounds in the literature because of their dynamic features which stem from their reversible interactions. Incorporating the ability for light to chemically modify these interactions provides a unique template for innovative, efficient and self-healing materials. This thesis explores the design, synthesis, and characterization of nine derivatives of a well-known organic compound – hemithioindigo – with dual function; as a photoswitch and a novel self-complementary hydrogen bond array. The supramolecular complexes formed moderate to strong associations (63 M-1 to 1100 M-1) with spontaneous Gibbs free energy values (-10.3 kJ/mol to -17.3 kJ/mol) to infer the effect of strong electron-withdrawing and electron-donating additions on each framework. Solid state complexation (via Single-Crystal X-Ray Crystallography) further confirmed the dimer structures of each photoarray. Photochemical and photophysical properties of these dynamic arrays were explored using UV-Vis and NMR spectroscopy with photostationary state (PSS) conversions to the E isomers from 12% to 82%.