Optical Sensor Applications of Carbazole Derivative Polymers Containing Different Aliphatic Groups Against Fe³⁺ Metal Ion

The carbazole derivatives containing aromatic rings with long alkyl groups such as C₆, C₈, C₁₀ and 3,4-bis(4-iodophenoxy) thiophene are synthesized. The products of carbazole derivatives and 3,4-bis(4-iodophenoxy) thiophene interaction were polymerized using FeCl₃ oxidant. The structural characteristics of the synthesized compounds were obtained by FT-IR and NMR spectroscopy. UV measurements are performed to determine the optical changes of the copolymers in the presence of metal ions such as Ag⁺, Cd²⁺, Co²⁺, Cu²⁺, Fe²⁺, Fe³⁺, Hg²⁺, Li⁺, Ni²⁺, Pb²⁺, Zn²⁺. The selectivity of Fe³⁺ is investigated by recording of the absorbance changes of Fe³⁺ solutions prepared at different concentrations. The effect of pH is also investigated in optical sensor studies. According to UV measurements, the materials containing thiophene and carbazole units can be considered as candidates for sensor production due to their selectivity towards Fe³⁺ ions.