Theoretical Study of the Molecular Complexes between Pyridyne and Acid Sites of Zeolites

The main interaction between pyridine and zeolites leads to form a hydrogen bond between the N atom of pyridine and OH groups of zeolites. The present work reports a theoretical study about the structural, vibrational and topological properties of the charge distribution of the molecular complexes between pyridine and a series of acids sites of zeolites. The calculated structural parameters are the highest occupied molecular orbital energy (EHOMO), lowest unoccupied molecular orbital energy (ELUMO), energy gap (ΔE), hardness (η), softness (S), the absolute electronegativity (χ), the electrophilicity index (ω) and the fractions of electrons transferred (ΔN) from zeolites molecules to pyridine. We show N atom of pyridine attacks to the H atom of the OH bridged group of zeolite clusters.