The ordinary FTIR search does not support a firm compound-level assignment for this sample. The nearest library hit is 1,2-thiazole, but all reported library similarities are effectively zero and there is no direct reference or related-literature confirmation. The measured spectrum is more safely described as a heteroaromatic ring-containing material, plausibly involving sulfur- and/or nitrogen-containing aromatic functionality, because the top library pattern repeatedly includes thiophene- and thiazole-type candidates while the sample shows multiple ring-region bands and a higher-wavenumber band near 3324 cm⁻¹ consistent with an X–H vibration. This direction remains broad because the available evidence does not securely establish a specific heterocycle or a single pure substance