Immobilization of the [RuII(edta)NO+] ion on the surface of functionalized silica gel

The reaction of NO and the immobilized dimer complex (edta)2Ru2(III 1/2 , III 1/2 ) on silica gel chemically modified with [3-(2-aminoethyl)aminopropyl]trimethoxysilane (AEATS) produces the corresponding immobilized nitrosyl complex AEATS/Ru II NO + . This compound, a monomer, was obtained by reducing the immobilized ruthenium dimer either electrochemically or with Eu" and reacting this species with NO 2 - ions. The properties of [Ru(edta)NO] - in solution and anchored (AEATS/Ru II NO + ) on silica were compared using electrochemical (DPV, CV) and spectroscopic (IR, UV-vis, and ESR) techniques. The results indicate that immobilization does not alter the reactivity of the ruthenium complex and confirm that [Ru(edta)(H 2 O)] 2- may be used, either in solution or immobilized, as a catalyst for the conversion of NO 2 - to NO + . Both the anchored nitrosyl complex AEATS/Ru II NO + and the [Ru(edta)NO] - species in solution, upon one-electron reduction, liberate NO at comparable rates.