Electronically and optically responsive thienothiophene-based polymers and their applications

Abstract

Responsive polymers, which are capable of responding to an external stimuli by changing their physical characteristics and/or chemical structures, have grown significantly during the previous two decades. Conjugated polymers' superior mechanical flexibility offers additional benefits for low-cost printable and wearable sensors applications, even though their operational and environmental stability still lags behind that of other organic semiconductor counterparts like single crystals and small molecules. The family of conjugated poly-electrolytes, thiophene-based polyelectrolytes has received a great deal of attention for their applications in bioanalytical studies. Supramolecular chemistry can be utilized to design sensors with a noteworthy affinity for a target analyte since it focuses primarily on noncovalent intermolecular and intramolecular interactions, which are weaker than covalent interactions. Thienotiophenes are promising building blocks in the creation of cutting-edge luminous substances for biomedical diagnostics because of their distinctive photophysical characteristics. We research potential chemoselective binding molecules to monitor biologically and toxicologically important ions and molecules based on thienothiophene-based polymers' capacity to provide an opto- and electro-responsive foundation. With six, seven, or eight glucopyranose units (-CD, -CD, -CD), cyclodextrins (CDs) are a novel class of cyclic oligosaccharide. These CD molecules have hydrophobic interiors and hydrophilic exteriors. It is beneficial for the formation of molecular complexes that CD molecules have a clearly defined cone-shaped chemical structure, providing these macromolecules with the ability of selective host-guest complex formation. Calixarenes are a subcategory of macrocyclic molecule with numerous uses in supramolecular chemistry. These molecular entities, which resemble well-organized vases, have been found to be of great use in building molecular recognition units. The prefabricated chambers of calixarenes make them suitable candidates for usage as host molecules. The calix[4]arene is the most extensively investigated calixarene-based receptor, even though many have been developed and investigated for its usage in supramolecular chemistry. Within the scope of this project, electronically and optically responsive materials, which play an important role in organic material chemistry will be discussed. In this work, novel thienothiophene-based polymers were designed and synthesized, the optical and electronic properties of materials were studied and device applications were investigated. Benefiting from the properties of thienothiophene-based polymers, the mentioned molecules were designed to have the ability to optically and electronically respond to biologically important ions and molecules. These new polymers are formed by units with electron-rich conjugated thienothiophene (TT) skeletons with thiophene (T) and biphenyl (BP) units as π-bridges. To develop the sensing media, considering their cone-shaped structure and their ability to form non-covalent interactions with the analyte, -cyclodextrin, and calix[4]arene were chosen. Thanks to the conjugated structures and -system electron flow in the design, molecules yielded high results in responsive materials studies. A comprehensive organic design planning for the synthesis stages of polymer materials was made and the optical (UV-Vis spectroscopy, fluorescence spectroscopy), electronic (CV, electrochemical coatings) properties of the resulting molecules and device application (Molecule and Ion Sensor) were examined. The synthetic steps were carried on through bromination, esterification, Suzuki coupling, and -78 C ketone addition. In this study, molecules with the ability to trap and sense biologically important molecules and ions in an aqueous media were designed.