CHEMICAL-REACTIVITY OF RUTHENIUM COMPLEXES SUPPORTED ON Y-TYPE ZEOLITES

The detailed chemical reactivity of the [RuII(NH3)5N2]2+ ion supported on a Y-type zeolite has been probed by infrared and UV-visible spectroscopy. The air oxidation of the supported ruthenium complex produces a winered species previously thought to be [RuIII(NH3)5OH]2+-Y. However, extensive spectral characterization of this material has revealed that the trimer, “ruthenium red”, has been formed on the zeolite support: [(NH3)5RuIII-O-RuIV(NH3)4-O-RuIII(NH3)5]6+-Y. Heat treatment of the [Ru(NH3)5N2]2+-Y species under vacuum produced a highly reactive ruthenium species, designated Ruac-Y, which chemically reacted with CO, NH3, and NO. The reaction with NH3 indicated that a Bronsted acid site interaction in the zeolite was involved. The reaction with CO could be interpreted as interaction with metal ion sites in the zeolite supercages. The absence of a CO-cation specific infrared band indicated that the oxidation state of the ruthenium in Ruac-Y is probably less than 2, i.e., small clusterssuch as Run° or Run+. The reaction of the active species and NO produced a material containing coordinated nitrosyl. No reaction could be observed for molecular nitrogen, H2S, or SO2. © 1979, American Chemical Society. All rights reserved.