Rotational Spectroscopy of Imidazole: Improved Rest Frequencies for Astrophysical Searches

Publication Summary

Originally published in Astronomy & Astrophysics, this study presents a comprehensive rotational spectroscopic investigation of imidazole, a five-membered nitrogen-containing ring that serves as a structural component of biologically important molecules such as histidine and purine nucleobases. The work was motivated by the need for more accurate spectroscopic data to support astronomical searches for imidazole in interstellar space, where previous efforts were limited by insufficient laboratory measurements.

Using broadband rotational spectroscopy and high-level quantum chemical calculations, the researchers recorded and analyzed the rotational spectrum of imidazole across frequencies from 2 to 295 GHz. The resulting spectroscopic dataset enabled the determination of improved molecular constants and highly accurate rest frequencies for future astrophysical observations. The study also evaluated astronomical survey data to constrain the abundance of imidazole in the star-forming region Sgr B2(N2), providing valuable reference data for future searches of prebiotically relevant molecules in space.