Time Courses of the Numbers of Spins from a Single or Two Organic Compounds on a Decationated Y-Type Zeolite

Abstract

Abstract The time courses of the number of organic radicals produced on the surface of a decationated Y-type zeolite (HY) were followed with electron paramagnetic resonance spectroscopy after the removal of heptane (a solvent). Regardless of the presence of the heptane, the relationship between the amount of adsorption and the number of spins for a binary system of HY and a single organic compound was linear and reversible, suggesting the significance of the presence of an adsorption equilibrium. On the surface of HY, there are two kinds of active sites possessing different times required for attaining constant numbers of spins. Cation radicals from a strong donor (perylene) adsorbed in advance on HY were gradually replaced by those from a weak donor (naphthalene), while a small number of cation radicals from naphthalene adsorbed in advance on HY remained after contact with a sufficiently large quantity of perylene. The coexistence of both donor and acceptor molecules on HY increased the number of both cations and anion radicals, which were significantly dependent on the order of adsorption.