Manganese (III) acetate

Structural formula
General
Surname	Manganese (III) acetate
other names	Manganese acetate Manganese triacetate
Molecular formula	C 6 H 9 MnO 6
Brief description	red-brown solid
External identifiers / databases
CAS number 993-02-2 (unspec.) 26935-72-8 (anhydrate) 19513-05-4 (dihydrate) EC number 213-602-5 ECHA InfoCard 100.012.365 PubChem 160554 Wikidata Q906315
properties
Molar mass	268.13 g mol −1 (dihydrate)
Physical state	firmly
safety instructions
GHS labeling of hazardous substances Dihydrate Caution H and P phrases H: 315-319-335 P: 261-305 + 351 + 338
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Manganese (III) acetate is a salt of trivalent manganese that is used as a mild and selective oxidizing agent. It belongs to the group of acetates with the constitutional formula Mn (CH ₃ COO) ₃ .

Extraction and presentation

Manganese (III) acetate dihydrate can be obtained by oxidizing manganese (II) acetate , which is dissolved in glacial acetic acid and heated. Potassium permanganate serves as the oxidizing agent :

${\displaystyle {\ce {4 Mn(C2H3O2)2 * 4 H2O + KMnO4 + 8 CH3CO2H ->}}}$ ${\displaystyle {\ce {5 Mn(C2H3O2)3 * 2 H2O + CH3CO2K + 10 H2O}}}$

Anhydrous manganese (III) acetate, on the other hand, can be obtained by reacting manganese (II) nitrate with acetic anhydride :

${\displaystyle {\ce {4 Mn(NO3)2 * 6 H2O + 30 (CH3CO)2O ->}}}$ ${\displaystyle {\ce {4 Mn(CH3CO2)3 + 8 NO2 + O2 + 48 CH3CO2H}}}$

properties

Like the analogous acetates of iron and chromium , the anhydrous form is a trinuclear complex bridged by three acetate pairs with a central oxygen atom. It crystallizes as a linear coordination polymer in which an additional acetate ion serves as a bridge. The free coordination point on the third manganese atom is saturated by an acetic acid molecule . The chemical is therefore not a simple triacetate and is not properly represented by the often used simple formula "Mn (OAc) ₃ ". The crystal structure of the hydrous form has not yet been clarified.

use

Manganese (III) acetate is used as:

• mild and selective oxidizing agent ,
• as a catalyst for allyl oxidations to generate alkenes ,
• as a reagent for the oxidative generation of radicals , e.g. for cyclizations ,
• as a starting material for acetoxylation reactions

Individual evidence

1. ↑ ^{a b c} Data sheet Manganese (III) acetate dihydrate, 97% from Sigma-Aldrich , accessed on October 4, 2011 ( PDF ).
2. ↑ Georg Brauer: Manganese (III) acetate . In: Handbook of Preparative Inorganic Chemistry . Ferdinand Enke Verlag, Stuttgart 1954, p. 1097-1098 .
3. ↑ El-Ahmadi I. Heiba, Ralph M. Dessau, William J. Koehl Jr .: oxidation by metal salts. III. Reaction of manganic acetate with aromatic hydrocarbons and the reactivity of the carboxymethyl radical. In: J. Am. Chem. Soc. 1969, 91, 1, pp. 138-145, doi : 10.1021 / ja01029a028 .
4. ↑ Hessel, LW; Romers, C .: The crystal structure of "anhydrous manganic acetate" . In: Recl. Trav. Chim. Pays-Bas . 88, 1969, pp. 545-552. doi : 10.1002 / recl.19690880505 .
5. ↑ Nam Ho Lee, Jong Seok Baik, Sung-bin Han: Development of Manganese (III) Acetate along with Schiff-Base Ligands as the Catalyst for the Oxygenation of Olefins in the O ₂ / NaBH ₄ System. In: Bulletin of the Korean Chemical Society. Volume 25, 2004 ( online ( Memento of the original from September 27, 2007 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this note. )