Ammonium permanganate

Ammonium permanganate
Names
IUPAC name
Ammonium manganate(VII)
Other names
Ammonium permanganate
Identifiers
3D model (JSmol)
ChemSpider
UN number 3085, 1482
  • InChI=1S/Mn.H3N.4O/h;1H3;;;;/q;;;;;-1/p+1 checkY
    Key: PASCZIGWJWZUOV-UHFFFAOYSA-O checkY
  • InChI=1/Mn.H3N.4O/h;1H3;;;;/q;;;;;-1/p+1/rMnO4.H3N/c2-1(3,4)5;/h;1H3/q-1;/p+1
    Key: PASCZIGWJWZUOV-AGRLYYGXAH
  • [O-][Mn](=O)(=O)=O.[N+]
  • [O-][Mn](=O)(=O)=O.[NH4+]
Properties
NH4MnO4
Molar mass 136.974 g/mol
Appearance rhombic needle crystals or powder with rich violet-brown or dark purple metallic sheen, become steel-gray in storage;
magenta–rose in solution
Density 2.2g/cm3, solid
Melting point decomposes
8.0 g/100 ml at 15 °C
Structure
Orthorhombic
Thermochemistry
J.K−1.mol−1
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
 Oxidant (O), Harmful (Xn), Dangerous for the environment (N)
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 0: Exposure under fire conditions would offer no hazard beyond that of ordinary combustible material. E.g. sodium chlorideFlammability 0: Will not burn. E.g. waterInstability 3: Capable of detonation or explosive decomposition but requires a strong initiating source, must be heated under confinement before initiation, reacts explosively with water, or will detonate if severely shocked. E.g. hydrogen peroxideSpecial hazard OX: Oxidizer. E.g. potassium perchlorate
0
0
3
OX
Safety data sheet (SDS) [ External MSDS]
Related compounds
Other anions
 Ammonium perrhenate
Other cations
 Sodium permanganate; Potassium permanganate
Related compounds
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

Ammonium permanganate is the chemical compound NH4MnO4, or NH3·HMnO4. It is a water soluble, violet-brown or dark purple salt.

Preparation

Ammonium permanganate was first prepared by Eilhard Mitscherlich in 1824 by reaction of silver permanganate with equal molar amount of ammonium chloride, filtering the silver chloride and evaporating the water.

AgMnO4 + NH4Cl → AgCl + NH4MnO4

It can also be prepared in a similar way from potassium permanganate and ammonium chloride.

KMnO4 +NH4Cl → KCl + NH4MnO4

Properties

Ammonium permanganate is a strong oxidizer, owing to its permanganate anion, and it is a moderately strong explosive, owing to the combination of oxidizer permanganate anion and reducing ammonium cation. Dry ammonium permanganate can detonate by heat, shock, or friction, and it may explode at temperatures above 140 °F (60 °C).[1]

Ammonium permanganate decomposes explosively to manganese dioxide, nitrogen, and water:[2]

2 NH4MnO4 → 2 MnO2 + N2 + 4 H2O

Ammonium permanganate decomposes slowly in storage even at normal temperatures. A sample stored for 3 months was only 96% pure, after 6 months it assumed color of iodine and had strong smell of nitrogen oxides. It emits toxic fumes when decomposed by heat.[3]

Quaternary ammonium permanganate compounds can be prepared, such as tetrabutylammonium permanganate[4] and benzyltriethylammonium permanganate.[5]

References

  1. ^ "MSDS Chemical Information File: Ammonium Permanganate". February 1988.
  2. ^ Chisholm, Hugh, ed. (1911). "Manganese" . Encyclopædia Britannica. Vol. 17 (11th ed.). Cambridge University Press. pp. 569–571.
  3. ^ Seymour M. Kaye (1978). "Permanganates - Ammonium Permanganate". Encyclopedia of Explosives and Related Items. Vol. 8. p. 178.
  4. ^ Sala, Tony; Sargent, Melvyn V. (1978). "Tetrabutylammonium permanganate: an efficient oxidant for organic substrates". Journal of the Chemical Society, Chemical Communications (6): 253–254. doi:10.1039/C39780000253.
  5. ^ Schmidt, H.-Jürgen; Schäfer, Hans J. (January 1979). "Oxidation of Hydrocarbons with Benzyl(triethyl)ammonium Permanganate". Angewandte Chemie International Edition in English. 18 (1): 68–69. doi:10.1002/anie.197900681.