The strengthening effect of a hydrogen or lithium bond on the Z···N aerogen bond (Z = Ar, Kr and Xe): a comparative study

Abstract

ABSTRACTAn ab initio study is performed on O3Z···NCM···NCX (Z = Ar, Kr and Xe; M = H and Li; X = H, F and CH3) complexes to investigate cooperativity effects between aerogen and hydrogen or lithium bonding interactions in these systems. To understand the cooperative effects, a detailed analysis of the binding distances, interaction energies and bonding properties is performed on these complexes. The results indicate that all Z···N and H/Li···N binding distances in the ternary complexes are shorter than those of corresponding binary systems. For a given M or X, cooperative energies increase as Z = Xe > Kr > Ar. Moreover, O3Z···NCLi···NCX complexes exhibit a larger cooperative energy than O3Z···NCH···NCX ones. The non-covalent interaction (NCI) index analysis indicates that the formation of an H/Li···N interaction in the ternary complexes shifts the location of the spike associated with the Z···N interaction towards the negative λ2ρ values. This indicates that NCI analysis can be regarded as a useful tool for the study of cooperative effects between two different non-covalent interactions. Also, cooperative effects in O3Z···NCM···NCX complexes make a decrease in 14N nuclear quadrupole coupling constants of NCH or NCLi molecule.