Manganese(III) has been stabilized in weakly acidic solution by pyrophosphate and the complex formed was elucidated spectrophotometrically. Stoichiometry of manganese(III) oxidation of ampicillin in pyrophosphate medium was established in the pH range 2.0–3.0 by iodometric and spectrophotometric methods. The oxidation follows frst order kinetics in [Mn(III)]. The effect of varying [Mn(III)], [A...

New manganese compounds [Mn(HphpzMe)(2)(H(2)phpzMe)(HCO(2))] (1), [Mn(2)(phpzMe)(2)(HphpzMe)(2)(OCH(3))]·2CH(3)OH (2), Na{[Mn(HphpzPh)(phpzPh)(MeOH)(2)](2)}(HCO(2)) (3), [Mn(HphpzPh)(2)(EtOH)(2)]ClO(4)·2EtOH (4) and [Mn(HphpzPh)(2)N(3)] (5) were synthesized and characterized with various techniques. 1, 4 and 5 are mononuclear manganese(III) compounds, 2 is a mixed-valence dinuclear manganese(II...

We use two-dimensional hyperfine sublevel correlation (HYSCORE) spectroscopy to investigate the coordination geometry of the nitrogen ligands of biomimetic models of the oxygen-evolving complex of photosystem II. In the 2D HYSCORE spectroscopy study, [(bpy)2Mn(III)(μ-O)2Mn(IV)(bpy)2](ClO4)3 (bpy, 2,2'-bipyridine) (1) and [H2O(terpy)Mn(III)(μ-O)2Mn(IV)(terpy)OH2](NO3)3 (terpy = 2,2':6',2″-terpyr...

In the title complex, [Mn(C20H14N2O2)Cl]·CH3OH, the central Mn(III) atom displays a distorted square-pyramidal coordination by two N and two O atoms from the tetradentate 2,2'-[1,2-phenyl-enebis(nitrilo-methanylyl-idyne)]diphenolate ligand and one chloride ligand. The Mn(III) atom is 0.525 (4) Å out of the square basal N2O2 least-squares plane. The complex mol-ecule is hydrogen bonded to the me...

The in vitro autoxidation of N-hydroxyurea (HU) is catalyzed by Mn(III)TTEG-2-PyP(5+), a synthetic water soluble Mn(III) porphyrin which is also a potent mimic of the enzyme superoxide dismutase. The detailed mechanism of the reaction is deduced from kinetic studies under basic conditions mostly based on data measured at pH = 11.7 but also including some pH-dependent observations in the pH rang...

The difference in electrostatics and reduction potentials between manganese ortho-tetrakis(N-ethylpyridinium-2-yl)porphyrin (MnTE-2-PyP) and manganese meta-tetrakis(N-ethylpyridinium-3-yl)porphyrin (MnTE-3-PyP) is a challenging topic, particularly because of the high likelihood for their clinical development. Hence, a detailed study of the protolytic and electrochemical speciation of Mn(II-IV)T...