The new 3-methyl-2-trifluoromethylchromone (1) and 3-bromomethyl-2-trifluoromethylchromone (2) compounds were synthesized and characterized by vibrational (IR, Raman), UV–Vis and NMR (¹H, ¹³C and ¹⁹F) spectroscopy and MS spectrometry. The crystal structures of 1 and 2 were determined by X-ray diffraction methods. Both compounds crystallize in the monoclinic P2₁/c space group with Z = 4 molecules per unit cell. The structures were solved from 1423 (1) and 1856 (2) reflections with I > 2σ (I) and refined by full-matrix least-squares to agreement R1-values of 0.0403 (1) and 0.0554 (2). Because of π-bonding delocalization, the organic molecular skeletons are planar and the molecular bonding structures can be described by formally single, double and resonant bonds. In 2, the single bond CF₃ group revealed a strong rotational disorder around the C single bond CF₃ bond, which could be explained in terms of four split positions with about uniform angular distribution. The vibrational, electronic and NMR, spectra were discussed and assigned with the assistance of DFT calculations.Centro de Química InorgánicaInstituto de Física La PlataFacultad de Ciencias Exactas