Information from IR fundamental and overtone spetra of diatomics adsorbed in zeolites NaCaA

From fundamental and overtone spectra of CO, NO and D2 adsorbed in zeolites NaCaA the constants of the internuclear potential can be derived for the adsorbed state. As the interactions with the zeolite surface are dominated by van der Waals forces, they remain less affected by adsorption. In contrast to diatomics adsorbed on transition metal surfaces, no considerable alteration of bond energy can be observed. The frequency shift is essentially due to the change of the harmonic force constant and indicates the interaction potential depending almost linearly on the vibrational state. The heterogeneity of the cation distribution inside the zeolites is reflected in the broadening of the adsorbate bands.