Manganese(III) fluoride
 |
|
| Names | |
|---|---|
| IUPAC name
Manganese(III) fluoride
|
|
| Other names
Manganese trifluoride, manganic fluoride
|
|
| Identifiers | |
7783-53-1  |
|
| ChemSpider | 74193 |
| Jmol 3D model | Interactive image |
| PubChem | 82213 |
| RTECS number | OP0882600 |
|
|
|
|
| Properties | |
| MnF3 | |
| Molar mass | 111.938 g/mol |
| Appearance | purple-pink powder hygroscopic |
| Density | 3.54 g/cm3 |
| Melting point | > 600 °C (1,112 °F; 873 K) (decomposes) |
| hydrolysis | |
| Structure | |
| Monoclinic, mS48 | |
| C2/c, No. 15 | |
| distorted octahedral | |
| Vapor pressure | {{{value}}} |
| Related compounds | |
|
Other anions
|
manganese(III) oxide, manganese(III) acetate |
|
Other cations
|
chromium(III) fluoride, iron(III) fluoride. cobalt(III) fluoride |
|
Related compounds
|
manganese(II) fluoride, manganese(IV) fluoride |
|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|
|
 verify (what is  ?) |
|
| Infobox references | |
Manganese(III) fluoride (also known as Manganese trifluoride) is the inorganic compound with the formula MnF3. This red/purplish solid is useful for converting hydrocarbons into fluorocarbons, i.e., it is a fluorination agent.[1] It also forms a hydrate.
Contents
Synthesis, structure and reactions
Synthesis
MnF3 can be prepared by treating a solution of MnF2 in hydrogen fluoride with fluorine:[2]
- MnF2 + 0.5 F2 → MnF3
It can also be prepared by the reaction of elemental fluorine with a manganese(II) halide at ~250 °C.[3]
Structure
In the crystalline state, MnF3 resembles vanadium(III) fluoride: both feature octahedral metal centers with the same average M-F bond distances. In the Mn compound, however, is distorted (and hence a monoclinic unit cell vs. a higher symmetry one) due to the Jahn-Teller effect, with pairs of Mn-F distances of 1.79, 1.91, 2.09 Å.[4][5][6]
The hydrate MnF3.3H2O is obtained by crystallisation of MnF3 from hydrofluoric acid. The hydrate is unusual in that it forms two different structures (both based on [Mn(H2O)4F2]+ [Mn(H2O)2F4]− ), which have space groups P21/c and P21/a.[7]
Reactions
MnF3 reacts with sodium fluoride to give the octahedral hexafluorate anion:[3]
- 3NaF + MnF3 → Na3MnF6
Other reaction conditions give compounds with anion formula MnF52− or MnF4−. These anions are chain and layer structures respectively, with bridging fluorine. Manganese remains 6 coordinate, octahedral, and trivalent in all these materials.[3]
Manganese(III) fluoride fluorinates organic compounds including aromatic hydrocarbons,[8] cyclobutenes,[9] and fullerenes.[10]
On heating, MnF3 decomposes to manganese(II) fluoride.[11][12]
Related Mn(III) compounds
Other manganese(III) compounds include manganese(III) acetate (CAS# 993-02-2), manganese acetylacetonate (CAS# 14284-89-0), Both are employed as oxidants in organic synthesis. MnF3 is Lewis acidic and forms a variety of derivatives. Two examples are K2MnF3(SO4)[13] and K2MnF5.
Safety considerations
Like other reactive inorganic fluorides, MnF3 should be stored in a polyethylene bottle and contact with skin or any other moist area avoided due to the formation of Hydrofluoric acid on hydrolysis.
See also
- CoF3, another fluorinating agent based on a transition metal in an oxidising +3 state.
References
- ↑ Burley, G. A.; Taylor, R. "Manganese(III) fluoride" in Encyclopedia of Reagents for Organic Synthesis (Ed: L. Paquette) 2004, J. Wiley & Sons, New York. doi:10.1002/047084289
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 3.0 3.1 3.2 Inorganic chemistry, Catherine E. Housecroft, A.G. Sharpe, pp.711-712, section Manganese (III) , googlebooks link
- ↑ Wells, A.F. (1984) Structural Inorganic Chemistry, Oxford: Clarendon Press. ISBN 0-19-855370-6.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Structures of two polymorphs of MnF3·3H2O , Michel Molinier and Werner Massa , Journal of Fluorine Chemistry , Volume 57, Issues 1-3, April–June 1992, pp.139-146 , online abstract via www.sciencedirect.com
- ↑ Fluorination of p-chlorobenzotrifluoride by manganese trifluoride A. Kachanov, V. Kornilov, V.Belogay , Fluorine Notes :Vol. 1 (1) November–December 1998 , via notes.fluorine1.ru
- ↑ Fluorination of fluoro-cyclobutene with high-valency metal fluoride m Junji Mizukado, Yasuhisa Matsukawa, Heng-dao Quan, Masanori Tamura, Akira Sekiya , Journal of Fluorine Chemistry Volume 127, Issue 1, January 2006, Pages 79-84 , online abstract via www.sciencedirect.com
- ↑ Fluorination of the cubic and hexagonal C60 modifications by crystalline manganese trifluoride , Physics of the Solid State , Volume 44, Number 4 , 4/2002 , pp.629-630 , V.É. Aleshina, A.Ya. Borshchevskii, E.V. Skokan, I.V. Arkhangel’skii, A.V. Astakhov, N.B. Shustova , online abstract via www.springerlink
- ↑ Manganese; section Manganic Salts via www.1911encyclopedia.org
- ↑ In situ time-resolved X-ray diffraction study of manganese trifluoride thermal decomposition , J.V. Raua, V. Rossi Albertinib, N.S. Chilingarova, S. Colonnab, U. Anselmi Tamburini, Journal of Fluorine Chemistry 4506 (2001) 1–4 , online version
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
Further reading
- Novel syntheses of some binary fluorides: the role of anhydrous hydrogen fluoride Acta Chim. Slov. 1999, 46(2), pp. 229–238, Zoran Mazej, Karel Lutar and Boris Žemva
- Knudsen Cell mass spectrometry study of Manganese Trifluoride vaporisation, High temperature corrosion and materials chemistry IV: proceedings of the International Symposium, pp. 521–525, google books
