Synthesis and characterization of polythiophene-based metallopolymers for smart applications

Conducting metallopolymers, a new class of hybrid materials containing π-conjugated polymer combined with metal complex, have attracted the attention of researchers in recent years with their promising properties. Metallopolymers attract attention not only since they combine the advantageous properties of metal complex and conjugated polymers, but also due to the new attractive properties provided by the interactions between the two units. Metallopolymers, in which the strength of the interactions between the two components can be adjusted according to the position of the metal in the polymer backbone, are used in the development of sensors, memory devices, photovoltaics, light-emitting diodes, electrochromic devices and stimulus-sensitive smart materials with these adjustable properties. So far, studies on the synthesis, characterization and electrochromic properties of conducting polymers containing metal complexes belong to Type II and Type III metallopolymer systems. Although there are studies on the synthesis and characterization of Type I metallopolymers in the literature, their optoelectronic properties were not investigated in any of these studies. In this study, it is aimed to evaluate the electrochromic properties of Type I metallopolymers and to introduce them to the literature. With this study, it is predicted that the new hybrid structures, which will be obtained by combining the electrochromic and redox properties of the metal complex and the conjugated backbone, will enable the development of multifunctional smart materials by providing different properties from the classical conducting polymer literature. Within the scope of this thesis novel ligands (Ligand a-h) and complex-containing monomers (Monomer A-H) were designed to investigate the possible effects of spacer group size and number of polymerizable units where [Ru2+(bpy)3] and [Ru2+(bpy)2triaz] were utilized as the transition metal complexes and SNS, EDOT and ProDOT as the polymerizable units. The redox properties of ligands and monomers were investigated by the cyclic voltammetry technique and suitable conditions for their electrochemical polymerization were evaluated and Polymer A-H homopolymers were obtained. Additionally, some of the monomers (Monomer A, B, C, D, E) were copolymerized in the presence of EDOT and ProDOT-Me2 by potentiodynamic or potentiostatic methods. The redox activities of all homopolymers and copolymers were investigated by the cyclic voltammetry technique. The optoelectronic properties of all polymers were evaluated by spectroelectrochemistry, kinetic and colorimetry studies. The relationship between the chemical structure and electrochemical (Monox, Polox/red, Rux/x) and optoelectronic (λmax , t95, ΔT, CE) properties of metallopolymers were analyzed considering the variation of complex unit, polymerizable unit and number of units. In addition, the effect of copolymerization, comonomer type and feed ratio on electrochemical and electrochromic properties were evaluated. With this study new, multichromic, ambipolar, cathodically and anodically colorable polythiophene-based metallopolymers having multiple redox activity were produced and the optoelectronic properties of Type I metallopolymers were investigated for the first time in the literature.