Combined DFT-experimental investigation and preparation of two new Thiadiazole-based Bithiophene or Fluorene containing polymers via Suzuki-Miyaura reactions

In this study, we firstly present an efficient synthetic pathway to a new Schiff base derivative (Sb) containing a thiadiazole backbone. In concomitant step, two newly designed polymers of this Schiff base derivative bearing bithiophene or fluorene subunits, abbreviated as poly[Sb-BTh] and poly[Sb-Flu], respectively, were prepared by surveying the Suzuki-Miyaura polycondensation reaction conditions. Following the completion of the synthetic steps, the appropriate structural analyses of the synthesized Schiff base and its corresponding bithiophene or fluorene bearing polymers were performed by using FT-IR, ¹H-NMR, ¹³C-NMR, GPC, DSC, and TGA analytical techniques. Furthermore, a detailed DFT-based computational study was also performed to enlighten the conformity between the experimental and theoretical findings by investigating the fundamental physical properties of the monomer and its oligomer units (n = 1–4). The experimental studies proved that the thermal stability of the poly[Sb-BTh] was found to be better than poly[Sb-Flu], and the computational studies were found to be consistent with the experimental outcomes.