Insight into the nature of the C...H−Cl/Li−Cl interactions in complexes of methane and ethane with hydrogen chloride and lithium chloride

In binary complexes of methane and ethane with HCl and LiCl, the effect of monomers orientation on C…H−Cl/Li−Cl bonding was studied using the MP2/aug-cc-pVTZ method. Calculations predict the formation of ethane complexes with “parallel” and “perpendicular” orientation of HCl/LiCl molecules relative to the CC covalent bond line of ethane. Decomposition of binding energy into components shows that in H-bonded complexes exchange repulsion and dispersion prevail over electrostatics and charge transfer. Stabilization of complexes with a Li-bond is mainly determined by the polarization component. Due to dispersion interactions, the perpendicular configuration of ethane complexes becomes more stable than the linear configuration.