To better understand the molecular definition of 3-[4-(trifluoromethyl)phenyl]-3a,4,8,8a-tetrahydro-6H-[1,3] dioxepino[5,6-d][1,2]oxazole (OXE–OXA) compound, we examined its molecular geometric structure and spectroscopic properties in detail. First, we determined the OXE–OXA compound’s crystal structure using single-crystal X-ray diffraction data, then we grew a single crystal of the OXE–OXA compound using the slow evaporation solution magnification technique at room temperature with ethanol. It was found that the OXE–OXA compound crystallizes in the monoclinic crystal system with the noncentrosymmetric space group P1 21/n1. We performed the theoretical calculations for OXE–OXA compound at the B3LYP/6-311++G(d,p) and HSEh1PBE/6-311++G(d,p) levels of the density functional theory method. According to the comparison of our obtained data, the experimental 1H and 13C nuclear magnetic resonance chemical shifts were in strong agreement with the values for simulated chemical shifts. Later, we investigated the experimental FT-IR and theoretical IR spectrum of OXE–OXA compounds in the 4000–400 cm–1 region.
