Chromium(III) acetylacetonate
| Chromium(III) acetylacetonate[1] | |
|---|---|
manganese(III)-3D-balls.png) | |
_acetylacetonate_Solid.jpg) Solid Chromium (III) acetylacetonate | |
| IUPAC name Chromium(III) acetylacetonate | |
| Other names tris(2,4-pentanediono)chromium(III) | |
| Identifiers | |
| CAS number | 21679-31-2  |
| ChemSpider | 2006256 |
| ChEBI | CHEBI:33035 |
| Jmol-3D images | {{#if:[Cr+3].O=C([CH-]C(=O)C)C.O=C([CH-]C(=O)C)C.O=C([CH-]C(=O)C)C|Image 1 |
| |
| |
| Properties | |
| Molecular formula | C15H21CrO6 |
| Molar mass | 349.32 |
| Appearance | deep maroon |
| Density | 1.34 g/cm3 |
| Melting point | 210 °C |
| Boiling point | 340 °C (sublimes near 100 °C) |
| Solubility in non-polar organic solvents | soluble |
(verify) (what is: / ?)Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa) | |
| Infobox references | |
Chromium(III) acetylacetonate is the coordination compound with the formula Cr(C5H7O2)3, sometimes designated as Cr(acac)3. This purplish coordination complex is used in NMR spectroscopy as a relaxation agent because of its solubility in nonpolar organic solvents and its paramagnetism.
Synthesis and structure
The compound is prepared by the reaction of chromium(III) oxide with acetylacetone (Hacac):[2]
- Cr2O3 + 6 Hacac → 2 Cr(acac)3 + 3 H2O
The complex has idealized D3 symmetry. The Cr-O distances are 1.93 Å.[3] Like other Cr(III) compounds, it has the d3 configuration, having a quartet ground state. Although it is relatively inert toward substitution, the complex undergoes bromination at the 3-positions of the chelate rings.
References
- ↑ Chromium acetylacetonate at American Elements
- ↑ W. Conard Fernelius, Julian E. Blanch “Chromium(III) Acetylacetonate: [Tris(2,4-Pentanediono)Chromium(III)]” Inorganic Syntheses, 1957, Volume 5, 130-131.doi:10.1002/9780470132364.ch35
- ↑ B. Morosin "The crystal structure of trisacetylacetonatochromium(III)" Acta Cryst. 1965. vol. 19, 131-137. doi:10.1107/S0365110X65002876