Conformational isomers of cis-chloro(nitrosyl)(1,4,7,10-tetraazacyclododecene)ruthenium(II), cis-[RuIICl(imcyclen)(NO+)]2+. Oxidation of the coordinated 1,4,7,10-tetraazacyclododecane (cyclen) ligand

The reaction of cis-dichloro(1,4,7,10-tetraazacyclododecane)ruthenium(III), cis-[RuIIICl2(cyclen)]+, in acidic aqueous solution, in the presence of nitric oxide, results in cis-[RuIICl(imcyclen)(NO+)]2+. The cis nitrosyl complex is precipitated as a mixture of two conformational isomers, which are separated by high performance liquid chromatography. Electrochemical, infrared spectroeletrochemistry, and infrared, UV–Vis, 1H NMR, and EPR spectra results indicate the presence of coordinated nitric oxide in the form of nitrosonium (NO+), and that the macrocyclic ligand (cyclen) is in the oxidized form in the complexes.