synthesis and properties of β-brominated metal complexes of meso-triphenylcorrole

Spectral properties and chemical stability of Mn(III), Mn(IV), Fe(III), Fe(IV), and Cu(III) complexes of beta-octabromotriphenylcorrole [(beta-Br)(8)(ms-Ph)(3)Cor], synthesized from beta-unsubstituted compounds by their reaction with molecular bromine, were studied. Cyclic voltammetry, electron microscopy, and X-ray spectral microanalysis were used to obtain electrochemical characteristics of metal corroles M(beta-Br)(8)(ms-Ph)(3)Cor and gain insight into the surface texture of active catalysts on the basis of metal corroles. The electron-acceptor beta-bromine substitution in the MCor macrocycle shifts the equilibrium in electron-donor solvents to lower oxidation states of the metals and also stabilizes manganese and destabilizes copper complexes in the protondonor medium HOAc-H2SO4. The electrocatalytic activity of the complexes in the reduction of molecular oxygen depends on the nature of the ligand and increases in the order Mn a parts per thousand currency sign Cu a parts per thousand(a) Fe in the case of beta-octabrominated macrocycles. The character of distribution of active centers on the surface of the catalysts was established for the first time.