Hydrothermal reaction of manganese(II) thiocyanate with trans-1,2-bis(4-pyridyl)ethylene (bpe) in water leads to the formation of the new ligand-rich 1 : 3 (ratio metal/ligand) compound [Mn(NCS)2(bpe)2·(bpe)] (1-Mn). In the crystal structure the manganese cations are octahedrally coordinated by two thiocyanato anions and four bpe ligands and are linked into layers by the bpe ligands. Reaction o...

In the natural environment, manganese is found as reduced soluble or adsorbed Mn(II) and insoluble Mn(III) and Mn(IV) oxides. Mn oxidation has been reported in various microorganisms. Several possible pathways, indirect or direct, have been proposed. A wider variety of Mn-reducing microorganisms, from highly aerobic to strictly anaerobic, has been described. The mechanisms of Mn reduction can b...

We studied the effect of manganese and various organic chelators on the distribution, depolymerization, and mineralization of synthetic 14C-labeled lignins (DHP) in cultures of Phanerochaete chrysosporium. In the presence of high levels of manganese [Mn(II) or Mn(III)], along with a suitable chelator, lignin peroxidase (LiP) production was repressed and manganese peroxidase (MnP) production was...

BACKGROUND Neurotoxicity and pulmonary dysfunction are well-recognized problems associated with prolonged human exposure to high concentrations of airborne manganese. Surprisingly, histological characterization of pulmonary responses induced by manganese remains incomplete. The primary objective of this study was to characterize histologic changes in the monkey respiratory tract following manga...

The present study focused on central nervous system (CNS) transport kinetics of manganese phosphate and manganese sulfate; these findings were correlated with the transport kinetics of manganese chloride (MnCl2), a model Mn compound that has been previously studied. A series of studies was performed to address the transport of Mn salts in confluent cultured endothelial cells. The initial rate o...

The role of bile in manganese metabolism and homeostasis was studied in Holstein bull calves fed diets containing 32 ppm manganese (normal) (control) or 1,000 ppm supplemental manganese (high-manganese) for 2 weeks before and 1 week after intravenous (IV) and duodenal S4Mn dosing. After dosing, all the bile was collected at 15 and 60 minutes, hourly to 12 hr and daily to 7 days. All calves were...

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...

The reactions of manganese(III) porphyrin complexes with terminal oxidants, such as m-chloroperbenzoic acid, iodosylarenes, and H(2)O(2), produced high-valent manganese(V)-oxo porphyrins in the presence of base in organic solvents at room temperature. The manganese(V)-oxo porphyrins have been characterized with various spectroscopic techniques, including UV-vis, EPR, 1H and 19F NMR, resonance R...

effects of imidazoles and substituted pyridines and pure s-donors on the oxidation of cyclooctene with naio4 by 5,10,15,20-tetraphenylporphyrinato-manganese(iii) acetate, mn(tpp)oac, and 5,10,15,20-tetramesitylporphyrinato-manganese(iii) acetate, mn(tmp)oac, catalysts in ch2cl2-h2o solvent are studied. coordination of the nitrogen donors to the mn-catalysts generally caused a reduction in the e...

Three high-nuclearity manganese(III) clusters have been synthesized and characterized: [Mn₈(μ₄-O)₄(phpzH)₈(thf)₄] (1), [Mn₈(μ₄-O)₄(phpzH)₄(EtOH)₄]·2EtOH (2), and [Mn₆(μ₃-O)₄(μ₃-Br)₂(HphpzEt)₆(phpzEt)] (3). Compounds 1 and 2 contain a [Mn₈(μ₄-O₄)(phpzH)₈] core in which antiferromagnetic interactions between the manganese(III) ions are found. Compound 3 is a hexanuclear manganese(III) cluster in ...