Structural Insights and Advanced Spectroscopic Characterization of Thiazolothiazoles: Unveiling Potential for Optoelectronic and Sensing Applications.

Thiazolothiazoles (TzTzs) are planar, π-conjugated heterocyclic compounds exhibiting unique structural and optoelectronic properties. In this study, a series of symmetrically substituted TzTz derivatives including imidazolyl, o-vanillyl, p-vanillyl, phenyl, thiazolyl, cinnamoyl, and trifluoromethylphenyl were synthesized and extensively characterized using X-ray crystallography (XRD), Fourier-transformed infrared (FTIR), nuclear magnetic resonance (NMR) and ultraviolet-visible (UV-Vis) spectroscopies, photoluminescence, X-ray absorption near edge structure (XANES, S K-edge), and density functional calculations. The compounds demonstrated diverse intermolecular interactions, including π×××π stacking and chalcogen bonding, which directly influenced their optical properties and electronic band structures. Several derivatives displayed promising features such as large Stokes shifts over 0.4 eV in solution and up to 1 eV in solid state, and reversible resistive switching behavior, positioning them as attractive candidates for use in optoelectronic devices and emerging memristive technologies.