Electrostatics driven interaction of dihydrogen with S-block metal cations: theoretical prediction of stable MH₁₆ complex

Abstract

Theoretical prediction of the formation of hydrogen-rich complexes of s-block metal ions and dihydrogen molecules, MH₁₆, (M = Li¹⁺, Na¹⁺, K¹⁺, Be²⁺, Ca²⁺, and Mg²⁺) is reported. The number of hydrogen molecules attached to the metal cation is the highest ever reported in the literature. The interaction between s-block metal ions and hydrogen is found to be weak and the binding energy calculated by MP2 method using cc-pVDZ basis set is observed to be of the order of -30 to -13.5 kcal/mol and -180 to -60 kcal/mol for alkali and alkaline earth metal cations, respectively. Using this simple ion-molecule interaction, the possibility of the application of these complexes for developing hydrogen storage materials is discussed.