Characteristics and nature of the intermolecular interactions between pyridine and various hydrides: A theoretical study

The nature of interactions of pyridine with various hydrides (Y) (Y = HF, HCl, H2O, H2S, NH3 and PH3) is investigated using ab initio calculations. The contribution of attractive (electrostatic, inductive, dispersive) and repulsive (exchange) components to the interactions energy is analyzed by using symmetry-adapted perturbation theory (SAPT). With the exception of pyridine-PH3 complexes, all the other pyridine-Y complexes favors σN-type H-bonding. Interaction energy decomposition reveals that σN-type complexes interactions are predominantly electrostatic in nature, while the dispersion and electrostatic interactions dominate the π-type complexes.