Manganese pentavalent

The most important manganese(V) compound is K MnO, a key intermediate in the manufacture of potassium permanganate. Potassium manganate(V) is an easily crystallized salt obtained by reduction of potassium permanganate using sodium sulfite in strong sodium hydroxide solution. This was the first compound to be recognized as exclusively pentavalent. 

Ferromanganese nodules and seamount crusts are characterized by distinct alternating layers of iron oxides and manganese oxides in addition to other components such as aluminosilicates (shale), CFA, and sometimes biogenic barite and carbonates in seamount crusts. Iron-oxide phases are enriched in elements that exist in normal seawater mainly as hydroxyl and carbonate complexes of tri- to pentavalent cations (e.g.. As, B, Bi, In, Ir, Rh, REEs, Y, Ti, Th, U, Zr, Hf, Nb, and Ta), oxyanions (e.g., P, Re, Ru, Os, S, Se, Te, V, and W), and divalent cations... 

Two oxidants essentially dominate these oxidations lead tetraacetate in organic solvents and periodic acid in aqueous media. On occasion, other oxidation reagents cause the cleavage of vicinal diols ceric ammonium nitrate [424], sodium bismuthate [482, 483], chromium trioxide [482, 555], potassium dichromate with perchloric acid [949], manganese dioxide [817], and trivalent [779, 789] or pentavalent [798] iodine compounds. 

It is also becoming increasingly apparent that the specific chemical form of a metal is a factor in its toxicity. Water-lipid partitioning, cell-wall permeability, and metabolic transport are just a few of the factors influenced by chemical form which, in turn, influence toxicity. Hexavalent chromium, pentavalent vanadium, divalent manganese, arsine, and methylmercury are more toxic than other forms of the corresponding metal. ... 

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