The reaction of NO and the immobilized dimer complex (edta)(2)Ru-2(III1/2,III1/2) on silica gel chemically modified with [3-(2-aminoethyl)aminopropyl]trimethoxysilane (AEATS) produces the corresponding immobilized nitrosyl complex AEATS/(RuNO+)-N-II. This compound, a monomer, was obtained by reducing the immobilized ruthenium dimer either electrochemically or with Eu-II and reacting this species with NO2- ions. The properties of [Ru(edta)NO](-) in solution and anchored (AEATS/(RuNO+)-N-II) 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)(H2O)](2-) may be used, either in solution or immobilized, as a catalyst for the conversion of NO2- to NO+. Both the anchored nitrosyl complex AEATS/(RuNO+)-N-II and the [Ru(edta)NO](-) species in solution, upon one-electron reduction, liberate NO at comparable rates.