LAUSR

Abstract Density functional theory (DFT) and MP2 calculation have been carried out in order to understand the ability of cation-π interaction to form half sandwiches and sandwiches of C C, Si Si and Ge Ge triple bond bridged via metal ions (Li + , Na + , K + , Mg 2+ and Ca 2+ ). Stability of such complexes is evaluated in terms of interaction energy and thermo-chemical parameters, enthalpy and free energy. Results predict a comprehensive stability of such half sandwiches/sandwiches in gas phase. In contrast to marked instability of complexes of other chosen cations in polar solvents, Mg 2+ complexes are considerably stable. Thermo-chemical analysis suggests that in both the cases the complexation process is enthalpy as well as free energy driven. Impact of cation-π interaction on the chosen π-systems is assessed by computing IR and UV–Visible spectra (using time dependent density functional theory (TD-DFT)) of the π-systems and their respective complexes.