The interaction of CCl4 with Ng (Ng = He, Ne, Ar), O2, D2O and ND3: rovibrational energies, spectroscopic constants and theoretical calculations

This investigation generated rovibrational energies and spectroscopic constants for systems of CCl4 with Ng (Ng = He, Ne, Ar), O2, D2O and ND3 from scattering experimental data, and the results presented are of interest for microwave spectroscopy studies of small halogenated molecules. The rovibrational spectra were obtained through two different approaches (Dunham and DVR) within the improved Lennard Jones (ILJ) model. Spectra were also generated within ordinary Lennard Jones and deviations suggest that the ILJ model should be preferred due to interactions beyond dispersion forces presented in these systems. Data from the literature and additional high level quantum mechanical calculations presented in this work show that these systems should not be considered as van der Waals complexes due to halogen bonding (HB) interactions, and this is especially true for the CCl4–D2O and CCl4–ND3 complexes. The charge displacement from the latter systems are one order of magnitude higher than the values from literature for CCl4 and He, Ne, Ar and O2 systems, and show significant deviations between DFT and Hartree-Fock values not previously reported in the literature.