Vibrational, electronic, and structural properties of 6-nitro- and 6-amino-2-trifluoromethylchromone: an experimental and theoretical study.

Two 2-trifluoromethylchromones, 6-nitro-2-trifluoromethylchromone (1) and 6-amino-2-trifluoromethylchromone (2) were synthesized and characterized by NMR ((1)H, (13)C, and (19)F), UV-vis, vibrational (IR and Raman) spectroscopy, MS spectrometry, and compound 1 also by single structural X-ray diffraction methods. This substance crystallizes in the monoclinic P2(1)/c space group with Z = 4 molecules per unit cell. In the solid, the fused rings and the amino group of 1 are coplanar and the trifluoromethyl group adopts a nearly staggered conformation. The NMR, vibrational, and electronic spectra were discussed and assigned with the assistance of DFT calculations.