THEORETICAL AND FTIR SPECTROSCOPIC STUDIES OF PLATINUM CARBONYL CLUSTERS ENCAPSULATED IN THE ZEOLITE CAGE

A suitable theoretical model makes possible to calculate the atomic, bond, and mean polarizabilities of the platinum carbonyl clusters encapsulated in zeolites. It has been found that the CO stretching frequencies depend on the charge on platinum and there exists a correlation between the CO vibrational frequencies and the mean polarizabilities of platinum carbonyl clusters. The CO stretching frequencies shifts toward higher frequencies with increasing polarizabilities of the clusters. Using the results of the mean polarizability calculation, from the infrared spectra of the CO molecules interacting with the Pt2+ ions exchanged into NaY zeolites, formation of the Chini cluster involving 12 Pt atoms can be established.