The trans-labilization of nitric oxide in Ru~(II) complexes by C-bound imidazoles

摘要

The synthesis,characterization and reactivity of trans-[NO(L)(NH_3)_4Ru]Cl_3(L=imidazole,theophylline and caffeine) are presented.~1H NMR spectroscopy indicates that theimidazole ligands are coordinated to the Ru~II through a carbonatom (imk~2 1,3Me_2Xank~8 and 1,3,7Me_3Xank~8).The nitrosyl stretching frequencies (v_NOapprox=1913 cm~(-1) suggest the coordianted nitrosyl has substantial NO~+ character.The complexes undergo a single-electron reduction(E~dge approx=-0.50V versus Ag/AgCl0,which involves thecoordinated nitrosyl.Dissociation of NO in th ereduced species is facilitated by releasing NO following reduction.