On the formation of sandwich complexes of aromatic inorganic linker: A DFT-D3 approach

Abstract

Density functional study is carried out to scrutinize the formation of half sandwich and sandwich complexes via cation···π interaction with alkali metal ions viz. Li+, Na+, K+, Rb+ and Cs+ at different theoretical levels. The complexation takes place between an anionic inorganic aromatic linker (cyclo-N5- or pentazolate ion), an alkali metal ion and organic/inorganic localized and delocalized π-system (benzene, borazine, ethene and oxygen). Polarization continuum model is used to scale the effect of solvent phase on the stability of the complexes. Results suggest that the complexes are stable in gas phase with stabilization energies lie within the range ~ 95.00–147.00 kcal mol−1. However, their stability is questionable in solvent phase with high dielectrics. The gas phase reaction is exothermic and spontaneous, and the process of complexation is enthalpy and free energy driven. The NBO analysis validates the role of π-systems as donor and metal cation as acceptor. QTAIM topological analysis suggests the presence of predominantly electrostatic interaction between the interacting monomers.