957110-75-7Relevant academic research and scientific papers
Two novel reactions of a ruthenium-coordinated phenazine - Oxidative aromatic ring hydroxylation and dimerization via a new C-N bond formation
Banerjee, Priyabrata,Mostafa, Golam,Castineiras, Alfonso,Goswami, Sreebrata
, p. 412 - 421 (2007)
The reaction of [Ru(CH3OH)2(N∧N) 2]2+ [N∧N = 2,2′-bipyridine (bpy) and 1,10-ortho-phenanthroline(phen)] with the phenazine ligand, [HL1 = 6-p-anisyl-2-(p-anisylamino)-3(4H)-p-anisylimine-9-methoxyphenazine] in the presence of a base (NEt3) afforded two mononuclear ruthenium complexes, [Ru(L1)(N∧N)2]X (2), and [Ru(LO)(N∧N)2]X2 (3), [LO = 7-methoxy-5-(4- methoxyphenyl)-2,3-bis(4-methoxyphenylimino)-3,5-dihydro-2H-phenazin-1-one] together with a diruthenium complex [(N∧N)2RuL 2Ru(N∧N)2]X3 (4), [L2 = 7,8′-dimethoxy-5,10′-bis(4-methoxyphenyl)-2,3′-bis(4- methoxyphenylamino)-3,2′-bis(4′-methoxyphenylimino)-3,5,2′, 10′-tetrahydro-[1,5′]biphenazinyl-5′-ylium], (X = ClO 4- or CF3SO3-). The complexes 3 and 4 were also obtained from the pure complex 2 under two different experimental condi-tions. Oxidative aromatic ring hydroxylation of the complex 2 produced 3 while the diruthenium complex, 4, was formed by dimerization of 2 via a new C-N bond formation. The products were thoroughly characterized with the help of 1H NMR and ESI-MS spectral measurements. Final authentication of the two coioeplexes of the transformed phenazine ligands viz. 3 and 4 were made by single-crystal X-ray structure determination of the two representative complexes. These compounds are intensely colored and show transitions in the visible region, which are ascribed as metal-to-ligand charge transfer (MLCT). Notably, intensities of the two MLCT of the compound 4 are significantly higher than those of 2 and 3. Redox properties of the complexes are reported. Electrochemical oxidation of compound 2, even in the presence of trace moisture, produced compound 3. Cyclic voltammetry of compound 3 shows a reductive response near -0.35 V. Its one-electron reduced product is blue and shows an intense EPR signal at g = 2.001. The voltammogram of the diruthenium complex 4 consists of two responses near 0.70 and 0.85 V. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
