A computational study of binary gas-phase complexes of propargylimine, a recently detected molecule in the interstellar medium, with the molecules HF and H2O

An MP2 and DFT computational study of binary complexes of propargylimine (PGIM) isomers with HF and H2O was undertaken; PGIM was discovered for the first time in the interstellar medium (ISM) in 2020. Fifteen stable hydrogen-bonded dyads were located and characterized. Intermolecular charge reorganization was investigated with natural bond orbital (NBO) analysis and is useful in rationalizing the structural and spectroscopic changes on complexation. Hydrogen bonding in PGIM was found to occur predominantly at four different atoms or subunits of the molecule, and the frequency shift of the HF molecule was identified as a distinctive indicator of the complexation site.

Automated summary

This computational study investigated binary complexes of propargylimine (PGIM) isomers with HF and H2O. Fifteen stable hydrogen-bonded dyads were identified and characterized. The intermolecular charge reorganization was analyzed using natural bond orbital (NBO) analysis, and the frequency shift of the HF molecule was found to indicate the complexation site.