PARAMAGNETIC SILVER COMPLEXES WITH AMMONIA IN ZEOLITES

The intermediate paramagnetic species formed in gamma-irradiated Ag-Na A zeolites with adsorbed ammonia have been studied by ESR spectroscopy . For zeolites with silver loadings of about one Ag+ ion per unit cell , the reaction of silver atoms with ammonia molecules above 180 K lead s to the formation of paramagnetic silver-ammonia adducts Ag.NH3 with the unpaired electron residing on both the silver and the nitrogen nuc lei. For silver loadings of about six Ag+ ions per unit cell, the form ation of binuclear silver complexes with two magnetically non-equivale nt Ag nuclei coordinated by NH3 ligands is proposed based on line shap e simulations of broad-line ESR septets.