DENSITY-FUNCTIONAL STUDIES OF WEAK BASE INTERACTIONS WITH HYDROXYL-GROUPS - MODELS FOR ADSORPTION COMPLEXES OF WEAK BASES IN MICROPOROUS MATERIALS

Density functional calculations, utilizing the BLYP and Becke3LYP func tionals, have been used to calculate the vibrational frequencies and i nteraction energies for a variety of intermolecular complexes modeling the interaction of weak bases with acidic hydroxyl groups in micropor ous materials. The interaction complexes of nitrogen, acetylene, ethen e, and benzene have been studied. Comparison is made between calculate d vibrational frequencies, vibrational frequency shifts, and interacti on energies with experimental determinations. Good agreement is observ ed between calculated vibrational properties and experimental determin ations for nitrogen, acetylene, and ethene interactions. Interaction e nergies are significantly underestimated in most cases.