Band Gap Studies on a Thermally Stable Polyimine Polymer and its Metal Complexes

A new polyimine polymer (PL) containing sulphone functional groups was prepared from polycondensation of Schiff base (L) with terephthaloyl chloride at a very moderate condition. The polymer metal complexes were then synthesized from the reaction of polymer with metal salts. Scanning electron microscope (SEM), Fourier‐transform infrared spectroscopy (FTIR), X‐ray diffraction analysis (XRD), thermal gravimetric analysis (TGA), derivative thermogravimetry (DTG), proton nuclear magnetic resonance (1H NMR), and CHNS elemental analysis have been used to characterize all the synthesized materials. The excellent thermal stability of PL was specified by TGA. The optical features were assessed with the UV‐visible technique. The polymer complexes represent absorbance at the same wavelength as L and PL. The synthesized polymer metal complexes have a band gap varying from 3.19 (CuPL) to 2.77 (CdPL) eV. The inherent viscosities for the synthesized polymer is 0.4490 dL/g in DMF at 25 °C, indicating their moderate molecular weight. A new and excellent thermally stable polyimine polymer containing sulphone functional groups with an inherent viscosity of 0.4490 dL/g synthesized from the corresponding monomer. Transition metal complexes of this polymer with Ag, Cd, Cu and Zn salts were synthesized with a very convenient procedure and results showed a band gap varying 3.19 (CuPL) to 2.77 (CdPL) eV.