In the presence of manganese oxides, dehydrosulfurization of various kinds of primary thioamides including aromatic, heterocyclic, and aliphatic ones efficiently proceeded to give the corresponding nitriles in high yields. The observed catalysis was truly heterogeneous, and manganese oxides could be reused.

We have synthesized a new tetranuclear manganese cluster with a distorted cubanelike [Mn4O4]-core. High field magnetization experiments reveal an intramolecular antiferromagnetic coupling between the four manganese ions. We explain our results both qualitatively and quantitatively by a simple spin square model in terms of four equal antiferromagnetic exchange interactions in the core with coupl...

Two types of manganese oxides have been prepared by hydrolysis of tetranuclear Mn(iii) complexes in the presence or absence of phosphate ions. The oxides have been characterized structurally using X-ray absorption spectroscopy and functionally by O2 evolution measurements. The structures of the oxides prepared in the absence of phosphate are dominated by di-μ-oxo bridged manganese ions that for...

Manganese is an essential metal that participates as a co-factor in a number of critical biological functions such as electron transport, detoxification of free radicals, and synthesis of neurotransmitters. Like other heavy metals, high concentrations of manganese are toxic. For example, chronic overexposure to manganese leads to movement disorders. In order to maintain this balance between bei...

This review provides an overview of the role, routes and effects of manganese in aquatic crustaceans. Manganese is a naturally abundant metal in marine and freshwater sediments where it is involved in a large number of chemical processes. Although sediments contain high natural concentrations of manganese, the potential danger to benthic organisms has been neglected in studies to date. Manganes...

Superoxide dismutase from chicken-liver mitochondria (manganese enzyme) and the two dismutases from Escherichia coli (manganese and iron enzymes) were analyzed through 29 cycles of automated Edman degradations. The high degree of homology among the amino-terminal sequences of these three dismutases corroborates their known similarity of structural and functional properties, and serves as furthe...

Maternal heat stress induced the aberrant epigenetic patterns resulting in the abnormal development of offspring embryos. It is unclear whether maternal dietary manganese supplementation as an epigenetic modifier could protect the chick embryonic development against maternal heat stress via epigenetic mechanisms. To test this hypothesis using an avian model, a completely randomized design with ...

UNLABELLED Several species of the bacterial genus Shewanella are well-known dissimilatory reducers of manganese under anaerobic conditions. In fact, Shewanella oneidensis is one of the most well studied of all metal-reducing bacteria. In the current study, a number of Shewanella strains were tested for manganese-oxidizing capacity under aerobic conditions. All were able to oxidize Mn(II) and to...

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 ...

For humans manganese is both an essential trace element and, at higher doses, a toxic metal. Due to the ubiquitous occurrence of manganese in foodstuff, in industrial countries daily dietary uptake is higher as compared to the estimated daily requirement. Therefore manganese deficiency is extremely rare. In contrast chronic manganese toxicity, affecting primarily the central nervous system, is ...