Triplet quantum-response functions

The interaction of the Cu ion in the lowest 3d ° singlet and 3d s triplet states with the ferrierite matrix was studied computationally [OlNl] by means of combined quantum mechanics/interatomic potential function technique [OOSl]. The excitation and emission energies found for the Cu-ferrierite and Cu-ZSM-5 systems were similar. The 540 and 480 mn peaks in the photoluminescence emission spectra were assigned to the Cu ion located on the chaimel intersection and on the walls of the main or perpendicular channels, respectively. The structure and coordination of individual binding sites of Cu in ferrierite were similar to those found in ZSM-5. Contrary to ZSM-5, the sites on the wall of the main and perpendicular channels of ferrierite are more stable than the sites located on the channel intersection. Thus, the population of the sites on the channel intersection will be lower in ferrierite than in ZSM-5. It was suggested that the differences in populations of the sites on the channel intersection found for ZSM-5 and ferrierite were responsible for the differences in catalytic activities of the systems. 

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