Electrochemical properties of Cu4[PhN3C6H4N3(H)Ph]4(µ-O)2, a tetranuclear Copper(II) complex with 1-phenyltriazenido-2-phenyltriazene-benzene as ligand

Abstract

IntroductionCompounds containing a chain with three nitrogen atoms, the triazenes, are largely described on the literature [1,2]. Among other uses, they were studied as chemotherapeutic agents. Triazenes and anionic triazenide ligands can show different types of coordination in metal complexes [1][2][3][4][5]. They can be monodentate, (N1,N3)-chelating towards one metal atom or (N1,N3)-bridging over two metal atoms.Compounds containing two chains of three nitrogen atoms, the bistriazenes, are also known [6][7][8][9][10][11][12][13][14]. The possibilities of coordination are enhanced when two nitrogen chains are present on the ligand. Complexes of ortho-, meta-and para-bis(phenyltriazene)benzenes ligands were synthesized and characterized. As expected, several different coordination types were observed. Bistriazenes show the coordination properties of triazenes and also the capacity to force close contacts between metal atoms.Although the structure of complexes with bistriazene ligands have been described, no reports were found in the literature related to electrochemical properties of these compounds. These studies are important for characterization and to a better understanding of their reactivity, stability and possible applications.The 1,2-bis(phenyltriazene)benzene ligand, C 6 H 5 NNN(H)C 6 H 4 NNN(H)C 6 H 5 , was used to synthesize the complex bis-(µ 2 -oxo)-tetrakis{[1-

Electrocatalytic O2 Reduction by Covalently Immobilized Mononuclear Copper(I) Complexes: Evidence for a Binuclear Cu2O2 Intermediate

“…[1][2][3][4][5] Several groups have studied molecular Cu complexes immobilized onto electrode surfaces as an entry into the study of 4-e O 2 reduction. [6][7][8][9][10][11][12][13][14][15][16][17][18][19] In particular, physisorbed copper(I) 1,10-phenanthroline, Cu(phen P ), reduces O 2 quantitatively by four electrons and four protons to water. [8][9][10] Anson et al determined that this reaction was first-order in Cu coverage, suggestive of a mononuclear Cu site as the active catalyst.…”

“…Discrete copper complexes are potential catalysts for the 4-electron (4-e) reduction of O 2 to water in ambient-temperature fuel cells, as evidenced by Cu-containing fungal laccase enzymes that rapidly reduce O 2 directly to water at a trinuclear Cu active site at remarkably positive potentials. − Several groups have studied molecular Cu complexes immobilized onto electrode surfaces as an entry into the study of 4-e O 2 reduction. − In particular, physisorbed copper(I) 1,10-phenanthroline, Cu(phen P ), reduces O 2 quantitatively by four electrons and four protons to water. − Anson et al determined that this reaction was first-order in Cu coverage, suggestive of a mononuclear Cu site as the active catalyst. , …”