Tuning tetrel bonds via cation–π interactions: an ab initio study on concerted interaction in M+–C6H5XH3–NCY complexes (M = Li, Na, K; X = Si, Ge; Y = H, F, OH)


In the present study, the M+–C6H5XH3–NCY (M = Li, Na, K; X = Si, Ge; Y = H, F, OH) complexes are investigated to find ways to enhance the X···N tetrel bond interactions. Cooperative effects are observed in complexes in which cation-π and tetrel bond interactions coexist. These effects are analysed in detail in terms of the energetic, geometric, charge-transfer and electron density properties of the complexes. The shortening of the tetrel bond distance in the ternary complexes is dependent on the strength of the cation-π interaction and it becomes larger in the order M = K < Na < Li. The cooperative energy ranges from −1.56 and −4.10 kcal/mol.