Carboxyl and ethynyl-substituted dithiafulvenes and tetrathiafulvalene vinylogues: synthesis, properties, and applications

Abstract

This thesis describes a systematic study of new dithiafulvene (DTF) and tetrathiafulvalene vinylogue (TTFV) derivatives as redox-active π-conjugated molecular materials. The content of this thesis work is divided into two major parts. In the first part, a series of carboxylate ester and carboxyl-substituted DTFs and TTFVs were synthesized and their electronic and electrochemical redox properties were characterized by UV-Vis spectroscopic and cyclic voltammetric analyses. The carboxyl-TTFV was applied as a redox-active ligand to complex with zinc ions, forming a stable Zn- TTFV coordination product. The structural, electrochemical, and thermal properties of the coordination product were investigated by infrared spectroscopy, powder X-ray diffraction, cyclic voltammetry, and differential scanning calorimetric analyses. Furthermore, the microscopic morphological and porosity properties of the Zn-TTFV coordination product were measured by scanning electron microscopy and nitrogen gas adsorption experiments. In the second part, a series of ethynyl-substituted DTF regioisomers was synthesized and then used as starting materials to construct further π-extended derivatives through oxidative dithiafulvenyl coupling and Cu-catalyzed alkynyl homocoupling reactions. The resulting π-conjugated systems were subjected to UV-Vis absorption and cyclic voltammetric analyses to examine their electronic properties and redox reactivity. Based on the characterization studies, a understanding of the structure-property-reactivity relationships for these compounds has been established.