New FTIR and DFT Study of (CH3)2CO ··· HCl Hydrogen-Bonded Complex

The study of hydrogen-bonded complexes is crucial for understanding intermolecular interactions that influence molecular structure, electron density distribution, and vibrational properties. In this work, we will investigate the acetone-hydrogen chloride (CH3)2CO···HCl complex using Fourier-transform infrared (FTIR) spectroscopy in cryogenic krypton and xenon solutions, alongside density functional theory (DFT) calculations. The experimental IR spectra reveal characteristic frequency shifts upon the complex formation, while the computational analysis provides insights into geometric and electronic structure changes. Topological analyses, including Atoms in Molecules (AIM) and Non-Covalent Interaction (NCI) approaches, confirm the presence and strength of hydrogen bonding. The study highlights solvent effects on vibrational properties and intermolecular interactions, advancing the understanding of the hydrogen bonding in complex molecular systems.