E P R study of the reaction of 8-quinolinoI with copper(II) ions in Y zeolites with different degree of hydration

According to the results of EPR spectroscopy associates of the complex molecules [Cu(ox)2] are formed on the external surface of the carrier by the reaction of 8-quinolinol (Hox) with highly mobile Cu(II) aqua complexes exchanged in the supercavities of fully hydrated Y zeolite. The reaction of Hox with Cu(II) exchanged zeolite Y, dehydrated in vacuo at 20 °C, 200 °C, and 400 °C, leads to segregated molecules of the [Cu(ox)2] complex fixed on zeolite. When the content of water in zeolite is lowered, migration of Cu(II) ions from the exchange sites on the walls of the cavities to the places, where they react with bulky molecules of Hox, becomes slower and the association of complex molecules is hindered. A small content of water in zeolite dehydrated at 200 °C accelerates remarkably the reaction of Cu(II) with Hox in compari­ son with the zeolite fully dehydrated at 400 °C. When the samples with fixed segregated molecules of the complex [Cu(ox)2] were rehydrated, the complex molecules formed associates in the hydrated layer on external surface of the zeolite.