Rovibrational spectroscopy of 1,4-dioxane in the mid-infrared range from high resolution jet-cooled and long path cell measurements.

This study presents a high-resolution rovibrational investigation of 1,4-dioxane in the mid-infrared region, motivated by the need for accurate spectroscopic data in the context of atmospheric monitoring of this emerging pollutant. Jet-cooled spectra were recorded using two complementary setups: a continuous supersonic jet coupled to the Fourier transform spectrometer of the AILES beamline at the SOLEIL synchrotron facility (Jet-AILES) and a quantum cascade laser spectrometer coupled to a pulsed jet (SPIRALES). These measurements were combined with long-path cell spectra at room temperature and supported by anharmonic quantum chemical calculations. Four fundamental vibrational bands (ν34, ν33, ν16, and ν15) were analyzed at high resolution, leading to the assignment of more than 6100 rovibrational transitions. A global fit yielded accurate ground- and excited-state rotational and centrifugal distortion parameters. The results significantly improve the spectroscopic characterization of 1,4-dioxane and provide reliable line lists for future atmospheric detection in the mid-infrared range.