Tris(acetylacetonato)iron(III)
{{chembox
|Watchedfields = changed
|verifiedrevid = 444564832
|ImageFile1 = Tris(acetylacetonato)iron(III)-2D-by-AHRLS-2012.png
|ImageSize1 = 150px
|ImageFile2 = Iron acetylacetonate complex ball.png
|ImageSize2 = 150px
|ImageFile3 = Sample of Fe(acac)3.JPG
|ImageSize3 = 150px
|IUPACName = Tris(2,4-dioxopentan-3-ido-κ2O,O′)iron
|OtherNames = Iron(III) acetylacetonate, Iron(III) tris(2,4-pentanedionato), Fe(acac)3
|Section1={{Chembox Identifiers
|CASNo = 14024-18-1
|CASNo_Ref = {{cascite|correct|CAS}}
|UNII_Ref = {{fdacite|correct|FDA}}
|UNII = 118BHF260P
|ChemSpiderID = 4588230
|EINECS = 237-853-5
|PubChem = 139087805
|SMILES = CC(=C[C-](C)O1)O[Fe+3]123(OC(=C[C-](C)O2)C)OC(=C[C-](C)O3)C
|StdInChI=1S/3C5H8O2.Fe/c3*1-4(6)3-5(2)7;/h3*3,6H,1-2H3;/q;;;+3/p-3/b3*4-3-;
|StdInChIKey = AQBLLJNPHDIAPN-LNTINUHCSA-K
}}
|Section2={{Chembox Properties
|Formula = Fe(C5H7O2)3
|Appearance = Red Solid
|Density = 1.348 g/cm3
|MolarMass = 353.17 g/mol
|MeltingPtC = 180 to 181
|BoilingPt = decomposes
|Solubility = 2 g/L
}}
|Section7={{Chembox Hazards
|GHSPictograms = {{GHS05}} {{GHS07}}
|GHSSignalWord = Danger
|HPhrases = {{H-phrases|H302 + H312 + H332 | H318}}
|PPhrases = {{P-phrases|P261 | P280 | P301 + P312 | P302 + P352 + P312 | P304 + P340 + P312 | P305 + P351 + P338}}
|GHS_ref = GHS: [https://www.sigmaaldrich.com/NL/en/product/aldrich/517003 Sigma-Aldrich 517003]
}}
}}
File:IR Spectrum of Tris(acetylacetonato)iron(III).png
Tris(acetylacetonato) iron(III), often abbreviated Fe(acac)3, is a ferric coordination complex featuring acetylacetonate (acac) ligands, making it one of a family of metal acetylacetonates. It is a red air-stable solid that dissolves in nonpolar organic solvents.
Preparation
Fe(acac)3 is prepared by treating freshly precipitated Fe(OH)3 with acetylacetone.{{US patent reference| number = 2004127690| y = 2004| m = 07| d = 01| inventor = Chaudhari, Mihir Kanti et al.| title = Process for making metal acetylacetonates}}
:Fe(OH)3 + 3 HC5H7O2 → Fe(C5H7O2)3 + 3 H2O
Structure and properties
Fe(acac)3 is an octahedral complex with six equivalent Fe-O bonds with bond distances of about 2.00 Å. The regular geometry is consistent with a high-spin Fe3+ core with sp3d2 hybridization. As the metal orbitals are all evenly occupied the complex is not subject to Jahn-Teller distortions and thus adopts a D3 molecular symmetry. In contrast, the related metal acetylacetonate Mn(acac)3 adopts a more distorted octahedral structure.{{cite journal | title = The infrared absorption spectra of metal acetylacetonates. | author = Lawson, K.E. | journal = Spectrochimica Acta | year = 1961 | volume = 17 | issue = 3| pages = 248–258 | doi = 10.1016/0371-1951(61)80071-4| bibcode = 1961AcSpe..17..248L }} The 5 unpaired d-electrons also result in the complex being paramagnetic, with a magnetic moment of 5.90 μB.
Fe(acac)3 possesses helical chirality. The Δ- and Λ-enantiomers slowly inter-convert via Bailar and Ray–Dutt twists. The rate of interconversion is sufficiently slow to allow its enantiomers to be partially resolved.Anders Lennartson "Optical resolution and racemisation of [Fe(acac)3]" Inorganica Chimica Acta 2011, vol. 365, pp. 451–453. {{doi|10.1016/j.ica.2010.07.066}}
Reactions
Fe(acac)3 has been examined as a precatalyst and reagent in organic chemistry, although the active iron-containing species is usually unidentified in these processes. In one instance, Fe(acac)3 was shown to promote cross-coupling a diene to an olefin.{{cite journal| title = Iron-Catalyzed Aminohydroxylation of Olefins|author1=Takacs, J. A., L. |author2=Madhavan, G.V. |author3=Creswell, M. |author4=Seely, F. |author5=Devroy, W. | journal = Organometallics| year = 1986| volume = 5| issue = 11| pages = 2395–2398| doi = 10.1021/om00142a044}} Fe(acac)3 catalyzes the dimerization of isoprene to a mixture of 1,5-dimethyl-1,5-cyclooctadiene and 2,5-dimethyl-1,5-cyclooctadiene.{{cite journal| title = Oligomerization of isoprene by cobalt or iron complex catalysts| author = Misono, A.| journal = Bulletin of the Chemical Society of Japan| year = 1966| volume = 39| issue = 11| pages = 2425–2429| doi=10.1246/bcsj.39.2425 | doi-access = free}}
:Image:Polymerization of Isoprene with Fe(acac)3.png
Fe(acac)3 also catalyzes the ring-opening polymerization of 1,3-benzoxazine.{{cite journal
| title = Highly efficient catalysts-acetylacetonato complexes of transition metals in the 4th period for ring-opening polymerization of 1,3-benzoxazine| first3 = Takeshi| last3 = Endo| first2 = Shoji| last2 =Hirayama | author = Sudo, A.| journal = Journal of Polymer Science Part A: Polymer Chemistry| year = 2010| volume = 48| issue = 2| pages = 479| doi = 10.1002/pola.23810| bibcode = 2010JPoSA..48..479S}} Beyond the area of polymerization, Fe(acac)3 has been found to catalyze the reaction of N-sulfonyl oxaziridines with olefins to form 1,3-oxazolidine products.{{cite journal| title = Iron-Catalyzed Aminohydroxylation of Olefins|author1=Williamson, K. T. |author2=Yoon, T. | journal = J. Am. Chem. Soc.| year = 2010| volume = 132| pmid = 20232850| issue = 13| pages = 4570–4571| pmc = 2857537| doi = 10.1021/ja1013536}}
