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Hypomanganate AI simulator
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Hub AI
Hypomanganate AI simulator
(@Hypomanganate_simulator)
Hypomanganate
In chemistry, hypomanganate, also called manganate(V) or tetraoxidomanganate(3−), is a trivalent anion (negative ion) composed of manganese and oxygen, with formula MnO3−
4.
Hypomanganates are usually bright blue. Potassium hypomanganate K
3MnO
4 is the best known salt, but sodium hypomanganate Na
3MnO
4, barium hypomanganate Ba
3(MnO
4)
2, and the mixed potassium-barium salt KBaMnO
4 is also known. The anion can replace phosphate PO3−
4 in synthetic variants of the minerals apatite and brownmillerite.
The manganate(V) anion was first reported in 1946 by Hermann Lux, who synthesized the intensely blue sodium hypomanganate by reacting sodium oxide Na
2O and manganese dioxide MnO
2 in fused sodium nitrite NaNO
2 at 500 °C. He also crystalized the salt from strong (50%) sodium hydroxide solutions as the decahydrate Na
3MnO
4·10H
2O.
Manganate(V) is a tetrahedral oxyanion structurally similar to sulfate, manganate, and permanganate. As expected for a tetrahedral complex with a d2 configuration, the anion has a triplet ground state.
The anion is a bright blue species with a visible absorption maximum at wavelength λmax = 670 nm (ε = 900 dm3 mol−1 cm−1).
Hypomanganate is unstable towards disproportionation to manganate(VI) and manganese dioxide: The estimated electrode potentials at pH 14 are:
However, the reaction is slow in very alkaline solutions (with OH− concentration above 5–10 mol/L).
The disproportionation is believed to pass through a protonated intermediate, with the acid dissociation constant for the reaction HMnO2−
4 ⇌ MnO3−
4 + H+ being estimated as pKa = 13.7 ± 0.2. However, K3MnO4 has been cocrystallized with Ca2Cl(PO4), allowing the study of the UV–visible spectrum of the hypomanganate ion.
Hypomanganate
In chemistry, hypomanganate, also called manganate(V) or tetraoxidomanganate(3−), is a trivalent anion (negative ion) composed of manganese and oxygen, with formula MnO3−
4.
Hypomanganates are usually bright blue. Potassium hypomanganate K
3MnO
4 is the best known salt, but sodium hypomanganate Na
3MnO
4, barium hypomanganate Ba
3(MnO
4)
2, and the mixed potassium-barium salt KBaMnO
4 is also known. The anion can replace phosphate PO3−
4 in synthetic variants of the minerals apatite and brownmillerite.
The manganate(V) anion was first reported in 1946 by Hermann Lux, who synthesized the intensely blue sodium hypomanganate by reacting sodium oxide Na
2O and manganese dioxide MnO
2 in fused sodium nitrite NaNO
2 at 500 °C. He also crystalized the salt from strong (50%) sodium hydroxide solutions as the decahydrate Na
3MnO
4·10H
2O.
Manganate(V) is a tetrahedral oxyanion structurally similar to sulfate, manganate, and permanganate. As expected for a tetrahedral complex with a d2 configuration, the anion has a triplet ground state.
The anion is a bright blue species with a visible absorption maximum at wavelength λmax = 670 nm (ε = 900 dm3 mol−1 cm−1).
Hypomanganate is unstable towards disproportionation to manganate(VI) and manganese dioxide: The estimated electrode potentials at pH 14 are:
However, the reaction is slow in very alkaline solutions (with OH− concentration above 5–10 mol/L).
The disproportionation is believed to pass through a protonated intermediate, with the acid dissociation constant for the reaction HMnO2−
4 ⇌ MnO3−
4 + H+ being estimated as pKa = 13.7 ± 0.2. However, K3MnO4 has been cocrystallized with Ca2Cl(PO4), allowing the study of the UV–visible spectrum of the hypomanganate ion.