In the present work, ab initio calculations are performed to investigate the geometry, interaction energy and bonding properties of binary complexes formed between metal-hydrides HMX (M = Be, Mg, Zn and X = H, F, CH 3 ) and a series of π -acidic heteroaromatic rings. In all the resulting com- plexes, the heteroaromatic ring acts as a Lewis acid (electron acceptor), while the H atom of the HMX molecule acts as a Lewis base (electron donor). The nature of this interaction, called ‘hydride- π ’inter- action, is explored in terms of molecular electrostatic potential, non-covalent interaction, quantum theory of atoms in molecules and natural bond orbital analyses. The results show that the interac- tion energies of these hydride- π interactions are between − 1.24 and − 2.72 kcal/mol. Furthermore, mutual influence between the hydride- π and halogen- or pnicogen-bonding interactions is stud- ied in complexes in which these interactions coexist. For a given π -acidic ring, the formation of the pnicogen-bonding induces a larger enhancing effect on the strength of hydride- π bond than the halogen-bonding.
