Synthesis and characterization of iminothiazole bearing polyphenol with adjustable white–yellow photoluminescence color

A new kind of thiazole based Schiff base, 2-[(benzothiazol-2-ylimino)methyl]phenol (2HBABT), was synthesized and then converted to its oligomer structure (O-2HBABT). Structural characterizations were made by Fourier transform infrared (FT-IR), nuclear magnetic resonance (NMR), size exclusion chromatography (SEC), and scanning electron microscopy (SEM) techniques. Optical properties were investigated by UV–vis and fluorescence analyses. Optical band gaps (Eg) were determined by absorption edges. Photoluminescence (PL) properties were determined in solution forms. Changes in PL characteristics in different solvents and applied excitation wavelengths were examined. O-2HBABT showed white and yellow emission colors in DMF by changing of applied excitation wavelength. Solid state electrical conductivities were measured by four-point probe technique. Cyclic voltammetry (CV) measurements were carried out and HOMO–LUMO energy levels and electrochemical band gaps (E′g) were calculated. Thermal data were obtained by TG-DTA and DSC techniques.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► A thiazole-based Schiff base oligomer was presented as a bicolored emitting material. ► Photoluminescence color of the oligomer could be adjusted as selectively white or yellow in DMF solution. ► HOMO–LUMO energy levels and electrochemical band gaps were calculated. ► Solid state electrical conductivity of the oligomer was found as 1.01 × 10−6 S cm−1.