Intermolecular weak interactions in HTeXH dimers (X=O, S, Se, Te): Hydrogen bonds, chalcogen-chalcogen contacts and chiral discrimination

A theoretical study of the HTeXH (X=O, S, Se and Te) monomers and homodimers was carried out by means of second-order Mller-Plesset perturbation theory (MP2) computational methods. In the case of monomers, the isomerization energy from HTeXH to H₂Te=X and H₂X=Te (X=O, S, Se, and Te) and the rotational transition-state barriers were obtained. Due to the chiral nature of these compounds, homo and heterochiral dimers were found. The electron density of the complexes was characterized with the atoms-in-molecules (AIM) methodology, finding a large variety of interactions. The charge transfer within the dimers was analyzed by means of natural bond orbitals (NBO). The density functional theory-symmetry adapted perturbation theory (DFT-SAPT) method was used to compute the components of the interaction energies. Hydrogen bonds and chalcogen-chalcogen interactions were characterized and their influence analyzed concerning the stability and chiral discrimination of the dimers.