Manganese(III) phosphate

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Manganese(III) phosphate
Names
Other names
  • Manganic phosphate
  • Manganese monophosphate
Identifiers
3D model (JSmol)
PubChem CID
  • InChI=1S/Mn.H3O4P/c;1-5(2,3)4/h;(H3,1,2,3,4)/q+3;/p-3
  • [O-]P(=O)([O-])[O-].[Mn+3]
Properties
MnPO4
Molar mass 149.91 g/mol (anhydrous)
167.92 g/mol (monohydrate)
AppearancePurple (anhydrous)
Pale-green (monohydrate)
Density 3.4 g/cm3 (anhydrous)
3.16 g/cm3 (monohydrate)
Melting point 400 °C (752 °F; 673 K) [1] (decomposes, anhydrous)
Insoluble [1]
Solubility Insoluble in acetonitrile, ethanol, and acetone [1]
Structure [1]
Orthorhombic
Pmna
a = 9.65 Å, b = 5.91 Å, c = 4.78 Å
272 Å3
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Manganese(III) phosphate is an inorganic chemical compound of manganese with the formula MnPO4. It is a hygroscopic purple solid that absorbs moisture to form the pale-green monohydrate, [1] though the anhydrous and monohydrate forms are typically each synthesized by separate methods.

Contents

Production and properties

Manganese phosphate monohydrate is produced by the reaction of an Mn(II) salt, such as manganese(II) sulfate, and phosphoric acid, followed by oxidation by nitric acid. Another method of producing the monohydrate is by the comproportionation of permanganate and Mn(II) in phosphoric acid: [2] [3] [4]

MnO4 + 4 Mn2+ + 10 PO43– + 8 H+ → 5 [Mn(PO4)2]3– + 4 H2O

The diphosphomanganate(III) ion slowly converts to the monohydrate. Heating of the monohydrate does not yield the anhydrous form, instead, it decomposes to manganese(II) pyrophosphate (Mn2P2O7) at 420 °C: [3]

4 MnPO4·H2O → 2 Mn2P2O7 + 4 H2O + O2

To produce the anhydrous form, lithium manganese(II) phosphate is oxidized with nitronium tetrafluoroborate under inert conditions. [1]

The anhydrous form is sensitive to moisture. In the absence of moisture, it decomposes at 400 °C, but when moisture is present, it slowly transitions to an amorphous phase and decomposes at 250 °C. [1]

Structure and natural occurence

Purpurite, the natural form of MnPO4 Purpurite - Sandamab Pegmatite, Erongo Region, Namibia 2.jpg
Purpurite, the natural form of MnPO4

The anhydrous form has an olivine structure and naturally occurs as the mineral purpurite. The monohydrate has a monoclinic structure, similar to that of magnesium sulfate monohydrate, but has distortions at the octahederal manganese center due to the Jahn-Teller effect. It naturally occurs as the mineral serrabrancaite. [5] [6] [7]

The monohydrate form has cell parameters of a = 6.912 Å, b = 7.470 Å, β = 112.3°, and Z = 4. It consists of interconnected distorted trans-[Mn(PO4)4(H2O)2] octahederons. [5]

Related Research Articles

<span class="mw-page-title-main">Copper(II) sulfate</span> Chemical compound

Copper(II) sulfate, also known as copper sulphate, is an inorganic compound with the chemical formula CuSO4. It forms hydrates CuSO4·nH2O, where n can range from 1 to 7. The pentahydrate (n = 5), a bright blue crystal, is the most commonly encountered hydrate of copper(II) sulfate. Older names for the pentahydrate include blue vitriol, bluestone, vitriol of copper, and Roman vitriol. It exothermically dissolves in water to give the aquo complex [Cu(H2O)6]2+, which has octahedral molecular geometry. The structure of the solid pentahydrate reveals a polymeric structure wherein copper is again octahedral but bound to four water ligands. The Cu(II)(H2O)4 centers are interconnected by sulfate anions to form chains. Anhydrous copper sulfate is a light grey powder.

<span class="mw-page-title-main">Calcium phosphate</span> Chemical compound

The term calcium phosphate refers to a family of materials and minerals containing calcium ions (Ca2+) together with inorganic phosphate anions. Some so-called calcium phosphates contain oxide and hydroxide as well. Calcium phosphates are white solids of nutritional value and are found in many living organisms, e.g., bone mineral and tooth enamel. In milk, it exists in a colloidal form in micelles bound to casein protein with magnesium, zinc, and citrate–collectively referred to as colloidal calcium phosphate (CCP). Various calcium phosphate minerals are used in the production of phosphoric acid and fertilizers. Overuse of certain forms of calcium phosphate can lead to nutrient-containing surface runoff and subsequent adverse effects upon receiving waters such as algal blooms and eutrophication (over-enrichment with nutrients and minerals).

<span class="mw-page-title-main">Manganese(II) chloride</span> Chemical compound

Manganese(II) chloride is the dichloride salt of manganese, MnCl2. This inorganic chemical exists in the anhydrous form, as well as the dihydrate (MnCl2·2H2O) and tetrahydrate (MnCl2·4H2O), with the tetrahydrate being the most common form. Like many Mn(II) species, these salts are pink, with the paleness of the color being characteristic of transition metal complexes with high spin d5 configurations.

<span class="mw-page-title-main">Permanganate</span> Chemical compound

A permanganate is a chemical compound with the manganate(VII) ion, MnO
4
, the conjugate base of permanganic acid. Because the manganese atom has a +7 oxidation state, the permanganate(VII) ion is a strong oxidising agent. The ion is a transition metal ion with a tetrahedral structure. Permanganate solutions are purple in colour and are stable in neutral or slightly alkaline media. The exact chemical reaction depends on the carbon-containing reactants present and the oxidant used. For example, trichloroethane (C2H3Cl3) is oxidised by permanganate ions to form carbon dioxide (CO2), manganese dioxide (MnO2), hydrogen ions (H+), and chloride ions (Cl).

<span class="mw-page-title-main">Gold(III) chloride</span> Chemical compound

Gold(III) chloride, traditionally called auric chloride, is an inorganic compound of gold and chlorine with the molecular formula Au2Cl6. The "III" in the name indicates that the gold has an oxidation state of +3, typical for many gold compounds. It has two forms, the monohydrate (AuCl3·H2O) and the anhydrous form, which are both hygroscopic and light-sensitive solids. This compound is a dimer of AuCl3. This compound has a few uses, such as an oxidizing agent and for catalyzing various organic reactions.

Permanganic acid (or manganic(VII) acid) is the inorganic compound with the formula HMnO4. This strong oxoacid has been isolated as its dihydrate. It is the conjugate acid of permanganate salts. It is the subject of few publications and its characterization as well as its uses are very limited.

<span class="mw-page-title-main">Monocalcium phosphate</span> Chemical compound

Monocalcium phosphate is an inorganic compound with the chemical formula Ca(H2PO4)2 ("AMCP" or "CMP-A" for anhydrous monocalcium phosphate). It is commonly found as the monohydrate ("MCP" or "MCP-M"), Ca(H2PO4)2·H2O. Both salts are colourless solids. They are used mainly as superphosphate fertilizers and are also popular leavening agents.

<span class="mw-page-title-main">Dicalcium phosphate</span> Chemical compound

Dicalcium phosphate is the calcium phosphate with the formula CaHPO4 and its dihydrate. The "di" prefix in the common name arises because the formation of the HPO42– anion involves the removal of two protons from phosphoric acid, H3PO4. It is also known as dibasic calcium phosphate or calcium monohydrogen phosphate. Dicalcium phosphate is used as a food additive, it is found in some toothpastes as a polishing agent and is a biomaterial.

Potassium hypomanganate is the inorganic compound with the formula K3MnO4. Also known as potassium manganate(V), this bright blue solid is a rare example of a salt with the hypomanganate or manganate(V) anion, where the manganese atom is in the +5 oxidation state. It is an intermediate in the production of potassium permanganate and the industrially most important Mn(V) compound.

Indium(III) sulfate (In2(SO4)3) is a sulfate salt of the metal indium. It is a sesquisulfate, meaning that the sulfate group occurs 11/2 times as much as the metal. It may be formed by the reaction of indium, its oxide, or its carbonate with sulfuric acid. An excess of strong acid is required, otherwise insoluble basic salts are formed. As a solid indium sulfate can be anhydrous, or take the form of a pentahydrate with five water molecules or a nonahydrate with nine molecules of water. Indium sulfate is used in the production of indium or indium containing substances. Indium sulfate also can be found in basic salts, acidic salts or double salts including indium alum.

<span class="mw-page-title-main">Manganese(II) sulfate</span> Chemical compound

Manganese(II) sulfate usually refers to the inorganic compound with the formula MnSO4·H2O. This pale pink deliquescent solid is a commercially significant manganese(II) salt. Approximately 260,000 tonnes of manganese(II) sulfate were produced worldwide in 2005. It is the precursor to manganese metal and many other chemical compounds. Manganese-deficient soil is remediated with this salt.

<span class="mw-page-title-main">Trimagnesium phosphate</span> Chemical compound

Trimagnesium phosphate describes inorganic compounds with formula Mg3(PO4)2.xH2O. They are magnesium acid salts of phosphoric acid, with varying amounts of water of crystallization: x = 0, 5, 8, 22.

<span class="mw-page-title-main">Copper(II) phosphate</span> Chemical compound

Copper(II) phosphate are inorganic compounds with the formula Cu3(PO4)2. They can be regarded as the cupric salts of phosphoric acid. Anhydrous copper(II) phosphate and a trihydrate are blue solids.

<span class="mw-page-title-main">Sodium bismuthate</span> Chemical compound

Sodium bismuthate is an inorganic compound, and a strong oxidiser with chemical formula NaBiO3. It is somewhat hygroscopic, but not soluble in cold water, which can be convenient since the reagent can be easily removed after the reaction. It is one of the few water insoluble sodium salts. Commercial samples may be a mixture of bismuth(V) oxide, sodium carbonate and sodium peroxide.

Manganese(II) phosphate is an inorganic compound with the chemical formula Mn3(PO4)2. It has industrial importance as a constituent of manganese based phosphate conversion coatings.

Barium permanganate is a chemical compound, with the formula Ba(MnO4)2. It forms violet to brown crystals that are sparingly soluble in water.

Vanadium phosphates are inorganic compounds with the formula VOxPO4 as well related hydrates with the formula VOxPO4(H2O)n. Some of these compounds are used commercially as catalysts for oxidation reactions.

Manganese phosphate may refer to:

Gold(III) phosphate is a chemical compound with the formula AuPO4. It is a pale yellow solid that is insoluble in water and acetone. It decomposes at 450 °C into gold metal, phosphorus pentoxide, and oxygen.

References

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  2. Eiichi Narita; Taijiro Okabe (1982). "Inhibition of catalytic decomposition of acid permanganate solutions". Industrial & Engineering Chemistry Product Research and Development. 21 (4): 662–666. doi:10.1021/i300008a030.
  3. 1 2 Narita Eiichi; Okabe Taijiro (1983). "The Thermal Decomposition of Manganese(III) Phosphate Monohydrate". Bulletin of the Chemical Society of Japan. 56 (9): 2841–2842. doi:10.1246/bcsj.56.2841.
  4. Slobotka Aleksovska; Vladimir M. Petruševski; Bojan Šoptrajanov (1997). "Infrared spectra of the monohydrates of manganese(III) phosphate and manganese(III) arsenate: relation to the compounds of the kieserite family". Journal of Molecular Structure. 408–409: 413–416. doi:10.1016/S0022-2860(96)09720-7.
  5. 1 2 Philip Lightfoot; Anthony K. Cheetham; Arthur W. Sleight (1987). "Structure of manganese(3+) phosphate monohydrate by synchrotron x-ray powder diffraction". Inorganic Chemistry. 26 (21): 3544–3547. doi:10.1021/ic00268a025.
  6. "Purpurite". mindat.org. mindat.org. Retrieved 5 September 2023.
  7. "Serrabrancaite". mindat.org. mindat.org. Retrieved 5 September 2023.