Design and synthesis of novel BODIPY polymeric dyes, and redoxactive tetrathiafulvalene-carbohydrate conjugates for potential biosensing applications

In this dissertation, 14 novel conjugated polymers based on BODIPY (4,4-Difluoro-4-bora-3a,4a-diaza- s-indacene) dye have been synthesized using a palladium-catalyzed Sonagashira reaction with triple bond connection. All these polymers have been characterized for optical and thermal properties. To demonstrate the hypothesis of synthetic feasibility and solubility of these polymers, we introduced several lengthy alkyl side chains to BODIPY-based polymers at meso position of BODIPY cores. These conjugated polymers emit in the deep-red region with absorption maxima up to 669 nm, emission spectral maximum up to 690 nm, and display significant red shifts (up to 173 nm and 180 nm) of both absorption and emission maxima compared to their starting BODIPY dyes, respectively, because of significant extension of pi-conjugation. These polymers exhibit good thermal stabilities (250-300°C) in a nitrogen atmosphere and are soluble in organic solvents like dichloromethane, THF, and DMF.To further demonstrate the functionalization and tunability of the BODIPY polymers, two ester functionalized and three co-monomers (phenyl, thiophene, fluorene) incorporated BODIPY conjugated polymers were prepared. For imaging applications, near IR emissive three BODIPY conjugated polymers were prepared with emission maxima up to 760 nm. The near-IR emission of these polymers was achieved by extending the conjugation through attaching styrene units to the BODIPY core using knoevenagel reaction and these monomers itself are near-IR emissive. Two deep-red emissive BODIPY co-polymers were also prepared for comparison studies. Finally, a water soluble, deep red emissive, conjugated BODIPY glyco-polymer bearing a alpha-D-mannose pendant was synthesized. All these polymers also display good thermal stabilities (300°C).Nine novel redox active carbohydrates were prepared based on the tetrathiafulvalene (TTF) molecule. The carbohydrates, to be precise, mannose, glucose, and galactose were attached to the TTF molecule in symmetric and asymmetric fashion. The asymmetric carbohydrate-TTF molecules were prepared with a sulfur or amine terminus to form SAMs (self assembled monolayers) on the electro active surfaces (e.g. gold and carbon nanotubes) for sensing applications. Mannose carbohydrate was attached to the TTF unit with different tethering chains of different lengths to demonstrate the synthesis flexibility and to optimize the redox signal in the sensing application.