Revision as of 19:57, 16 February 2012 editBeetstra (talk | contribs)Edit filter managers, Administrators172,031 edits Saving copy of the {{chembox}} taken from revid 473754783 of page Acetylacetone for the Chem/Drugbox validation project (updated: ''). |
Latest revision as of 15:33, 21 December 2024 edit Preimage (talk | contribs)Extended confirmed users913 edits Minor copyediting |
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{{redirect|Acac|other uses|ACAC (disambiguation)}} |
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{{ambox | text = This page contains a copy of the infobox ({{tl|chembox}}) taken from revid of page ] with values updated to verified values.}} |
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{{chembox |
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{{Chembox |
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| Watchedfields = changed |
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| verifiedrevid = 443366220 |
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| verifiedrevid = 477240155 |
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| ImageFile = AcacH.png |
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| ImageFile = Acetyloaceton.svg |
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| ImageSize = 260px |
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| ImageSize = 150px |
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| ImageName = Skeletal structures of both tautomers |
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| ImageName = Skeletal structures of both tautomers |
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| ImageFileL1 = Acetylacetone-enol-3D-balls.png |
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| ImageFileL1 = Acetylacetone-enol-tautomer-from-xtal-Mercury-3D-balls.png |
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| ImageSizeL1 = 130px |
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| ImageNameL1 = Ball-and-stick model of the enol tautomer |
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| ImageNameL1 = Ball-and-stick model of the enol tautomer |
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| ImageFileR1 = Acetylacetone-keto-3D-balls.png |
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| ImageFileR1 = Acetylacetone-keto-tautomer-from-xtal-Mercury-3D-balls.png |
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| ImageSizeR1 = 130px |
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| ImageNameR1 = Ball-and-stick model of the keto tautomer |
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| ImageNameR1 = Ball-and-stick model of the keto tautomer |
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| ImageFileL2 = Acetylacetone-enol-tautomer-from-xtal-Mercury-3D-sf.png |
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|IUPACName=Pentane-2,4-dione |
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| ImageNameL2 = Space-filling model of the enol tautomer |
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|OtherNames=Hacac |
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| ImageFileR2 = Acetylacetone-keto-tautomer-from-xtal-Mercury-3D-sf.png |
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|Section1={{Chembox Identifiers |
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| ImageNameR2 = Space-filling model of the keto tautomer |
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| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} |
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| IUPACName = (3Z)-4-Hydroxy-3-penten-2-one ''(enol form)''<br>Pentane-2,4-dione ''(keto form)'' |
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| OtherNames = {{ubl|Hacac|2,4-Pentanedione}} |
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| Section1 = {{Chembox Identifiers |
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| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} |
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| ChemSpiderID = 29001 |
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| ChemSpiderID = 29001 |
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| KEGG_Ref = {{keggcite|correct|kegg}} |
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| KEGG_Ref = {{keggcite|correct|kegg}} |
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| InChI = 1/C5H8O2/c1-4(6)3-5(2)7/h3H2,1-2H3 |
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| InChI = 1/C5H8O2/c1-4(6)3-5(2)7/h3H2,1-2H3 |
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| InChIKey = YRKCREAYFQTBPV-UHFFFAOYAO |
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| InChIKey = YRKCREAYFQTBPV-UHFFFAOYAO |
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| SMILES1 = CC(=O)CC(=O)C |
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| ChEMBL_Ref = {{ebicite|correct|EBI}} |
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| ChEMBL_Ref = {{ebicite|correct|EBI}} |
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| ChEMBL = 191625 |
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| ChEMBL = 191625 |
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| CASNo_Ref = {{cascite|correct|CAS}} |
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| CASNo_Ref = {{cascite|correct|CAS}} |
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| CASNo=123-54-6 |
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| CASNo=123-54-6 |
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| UNII_Ref = {{fdacite|correct|FDA}} |
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| UNII_Ref = {{fdacite|correct|FDA}} |
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| UNII = 46R950BP4J |
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| UNII = 46R950BP4J |
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| ChEBI_Ref = {{ebicite|correct|EBI}} |
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| ChEBI_Ref = {{ebicite|correct|EBI}} |
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| ChEBI = 14750 |
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| ChEBI = 14750 |
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| PubChem = 31261 |
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| RTECS = SA1925000 |
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| UNNumber = 2310 |
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| Beilstein = 741937 |
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| Gmelin = 2537 |
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| EINECS = 204-634-0 |
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| SMILES = O=C(C)CC(=O)C |
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| SMILES = O=C(C)CC(=O)C |
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| SMILES1 = CC(=O)CC(=O)C |
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| SMILES2 = CC(O)=CC(=O)C |
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| SMILES2_Comment = ] |
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}} |
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| Section4 = {{Chembox Properties |
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| C=5|H=8|O=2 |
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| Appearance = Colorless liquid |
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| Density = 0.975 g/mL<ref>{{cite web|url=http://www.sigmaaldrich.com/catalog/product/sial/05581?lang=en®ion=GB|website=Sigma-Aldrich|title=05581: Acetylacetone}}</ref> |
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| MeltingPtC = −23 |
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| BoilingPtC = 140 |
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| Solubility = 16 g/(100 mL) |
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| Solvent = Water |
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| MagSus = −54.88·10<sup>−6</sup> cm<sup>3</sup>/mol |
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}} |
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| Section5 = {{Chembox Hazards |
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| NFPA-H = 2 |
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| NFPA-F = 2 |
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| NFPA-R = 0 |
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| GHSPictograms = {{GHS02}}{{GHS06}}{{GHS07}}{{GHS08}} |
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| GHSSignalWord = Danger |
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| HPhrases = {{H-phrases|226|302|311|320|331|335|341|370|412}} |
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| PPhrases = {{P-phrases|201|202|210|233|240|241|242|243|260|261|264|270|271|273|280|281|301+312|302+352|303+361+353|304+340|305+351+338|307+311|308+313|311|312|321|322|330|337+313|361|363|370+378|403+233|403+235|405|501}} |
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| FlashPtC = 34 |
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| AutoignitionPtC = 340 |
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| ExploLimits = 2.4–11.6% |
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}} |
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}} |
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}} |
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|Section4={{Chembox Properties |
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'''Acetylacetone''' is an ] with the chemical formula {{chem2|CH3\sC(\dO)\sCH2\sC(\dO)\sCH3}}. It is classified as a 1,3-]. It exists in equilibrium with a ] {{chem2|CH3\sC(\dO)\sCH\dC(\sOH)\sCH3}}. The mixture is a colorless liquid. These tautomers interconvert so rapidly under most conditions that they are treated as a single compound in most applications.<ref>{{cite encyclopedia|title=2,4-Pentanedione|encyclopedia= e-EROS Encyclopedia of Reagents for Organic Synthesis|author=Thomas M. Harris|doi=10.1002/047084289X.rp030|year=2001|isbn= 0471936235}}</ref> Acetylacetone is a building block for the synthesis of many ]es as well as ]s. |
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|Formula=C<sub>5</sub>H<sub>8</sub>O<sub>2</sub> |
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|MolarMass=100.13 g/mol |
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==Properties== |
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|Density=0.98 g/mL |
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|MeltingPt=−23 °C |
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=== Tautomerism === |
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|BoilingPt=140 °C |
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{| class="wikitable" style="float: left; margin: 1em;" |
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|Solubility=16 g/100 mL |
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|Solvent=Water} |
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! Solvent !! ''K''<sub>keto→enol</sub> |
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pKa=9 in water<ref name="Evan's pKa table">Evan's pKa table</ref> |
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pKa=13.3 in DMSO<ref name="Evan's pKa table"/> |
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| ] || 11.7 |
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}} |
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|Section15={{Chembox Hazards |
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| ] || 42 |
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|EUClass=Harmful ('''Xn''') |
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|EUIndex=606-029-00-0 |
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| ] || 10 |
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|NFPA-H=2 |
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|NFPA-F=2 |
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| ] || 7.2 |
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|NFPA-R=0 |
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|RPhrases={{R10}}, {{R22}} |
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| ]<ref>{{cite journal |last1=Smith |first1=Kyle T. |last2=Young |first2=Sherri C. |last3=DeBlasio |first3=James W. |last4=Hamann |first4=Christian S. |title=Measuring Structural and Electronic Effects on Keto–Enol Equilibrium in 1,3-Dicarbonyl Compounds |journal=Journal of Chemical Education |date=12 April 2016 |volume=93 |issue=4 |pages=790–794 |doi=10.1021/acs.jchemed.5b00170|bibcode=2016JChEd..93..790S }}</ref> || 5.7 |
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|SPhrases={{S2}}, {{S21}}, {{S23}}, {{S24/25}} |
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|FlashPt=34 °C |
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| ] || 2 |
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|Autoignition=340 °C |
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|ExploLimits=2.4–11.6% |
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| ] || 0.23 |
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}} |
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} |
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] |
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The ] ] of acetylacetone coexist in solution. The enol form has C<sub>2v</sub> ], meaning the hydrogen atom is shared equally between the two oxygen atoms.<ref>{{cite journal |
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|title=The C<sub>2v</sub> Structure of Enolic Acetylacetone |
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|first1=W.|last1=Caminati|first2=J.-U.|last2=Grabow|year=2006 |
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|journal=]|volume=128|issue=3|pages=854–857|doi=10.1021/ja055333g|pmid=16417375 |
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}}</ref> In the gas phase, the ], ''K''<sub>keto→enol</sub>, is 11.7, favoring the enol form. The two tautomeric forms can be distinguished by ], ] and other methods.<ref>{{cite journal |
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|title=Substituent Effects on Keto–Enol Equilibria Using NMR Spectroscopy |
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|first1=Kimberly A.|last1=Manbeck|first2=Nicholas C.|last2=Boaz|first3=Nathaniel C.|last3=Bair|first4=Allix M. S.|last4=Sanders|first5=Anderson L.|last5=Marsh|year=2011 |
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|journal=]|volume=88|issue=10|pages=1444–1445|doi=10.1021/ed1010932 |
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|bibcode=2011JChEd..88.1444M}}</ref><ref>{{cite journal |
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|title=Intramolecular hydrogen bond in enol form of 3-substituted-2,4-pentanedione|journal=]|year=1970|volume=26|issue=24|pages=5691–5697|doi=10.1016/0040-4020(70)80005-9|first1=Z.|last1=Yoshida|first2=H.|last2=Ogoshi|first3=T.|last3=Tokumitsu}}</ref> |
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The equilibrium constant tends to be high in nonpolar solvents; when ''K''<sub>keto→enol</sub> is equal or greater than 1, the enol form is favoured. The keto form becomes more favourable in polar, hydrogen-bonding solvents, such as water.<ref>{{cite book|title=Solvents and Solvent Effects in Organic Chemistry|first=Christian|last=Reichardt|publisher=Wiley-VCH|edition= 3rd|date= 2003|isbn=3-527-30618-8}}</ref> The enol form is a ] analogue of a ].{{citation needed|date=May 2024}}{{clear|left}} |
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=== Acid–base properties === |
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{| class="wikitable" style="float: left; margin: 1em;" |
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!Solvent!!T/°C!!p''K''<sub>a</sub><ref name=scdb> {{Webarchive|url=https://web.archive.org/web/20170619235720/http://www.acadsoft.co.uk/scdbase/scdbase.htm |date=2017-06-19}} A comprehensive database of published data on equilibrium constants of metal complexes and ligands</ref> |
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|40% ]/water||30||9.8 |
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|70% ]/water||28||12.5 |
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|80% ]/water||25||10.16 |
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|DMSO||25||13.41 |
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Acetylacetone is a ]. It forms the acetylacetonate ] {{chem2|C5H7O2−}} (commonly abbreviated '''{{chem2|acac−}}'''): |
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:{{chem2|C5H8O2 ⇌ C5H7O2− + H+}} |
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] |
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In the acetylacetonate anion, both ]-] bonds are equivalent. Both C-C central bonds are equivalent as well, with one ] atom bonded to the central carbon atom (the ]). Those two equivalencies are because there is a ] between the four bonds in the ] in the acetylacetonate anion, where the ] of those four bonds is about 1.5. Both ] atoms equally share the ]. The acetylacetonate anion is a ] ]. |
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] recommended ] values for this equilibrium in aqueous solution at 25 °C are 8.99 ± 0.04 (''I'' = 0), 8.83 ± 0.02 (''I'' = 0.1 ] ]) and 9.00 ± 0.03 (''I'' = 1.0 M {{chem2|NaClO4}}; ''I'' = ]).<ref>{{cite journal|last1=Stary|first1=J.|last2=Liljenzin|author2-link=Jan-Olov Liljenzin|first2= J. O.|year=1982|title=Critical evaluation of equilibrium constants involving acetylacetone and its metal chelates|volume=54|issue=12|pages=2557–2592| doi=10.1351/pac198254122557| url=http://www.iupac.org/publications/pac/pdf/1982/pdf/5412x2557.pdf|journal=Pure and Applied Chemistry|s2cid=96848983}}</ref> Values for mixed solvents are available. Very strong ], such as ] compounds, will ] acetylacetone twice. The resulting dilithium species can then be ] at the ] atom at the ].{{clear|left}} |
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==Preparation== |
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Acetylacetone is prepared industrially by the thermal rearrangement of ].<ref>{{cite encyclopedia|encyclopedia=]|location=Weinheim |publisher=Wiley-VCH |first1=Hardo|last1=Siegel|first2=Manfred|last2=Eggersdorfer|chapter=Ketones|doi=10.1002/14356007.a15_077|date=2002|isbn=9783527306732 }}</ref> |
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] |
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Laboratory routes to acetylacetone also begin with ]. Acetone and ] ({{chem2|(CH3C(O))2O}}) upon the addition of ] ({{chem2|BF3}}) catalyst:<ref name = denoon>{{OrgSynth | title = Acetylacetone | first1 = C. E. Jr. |last1 =Denoon | first2 =Homer| last2 =Adkins| first3 =James L.| last3 =Rainey | volume = 20 | page = 6 | doi = 10.15227/orgsyn.020.0006|year=1940}}</ref> |
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:{{chem2|(CH3C(O))2O + CH3C(O)CH3 → CH3C(O)CH2C(O)CH3}} |
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A second synthesis involves the base-catalyzed condensation (e.g., by ] {{chem2|CH3CH2O-Na+}}) of acetone and ], followed by acidification of the ] (e.g., by ] HCl):<ref name = denoon/> |
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:{{chem2|CH3CH2O-Na+ + CH3C(O)OCH2CH3 + CH3C(O)CH3 → Na+ + 2 CH3CH2OH}} |
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:{{chem2|Na+ + HCl → CH3C(O)CH2C(O)CH3 + NaCl}} |
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Because of the ease of these syntheses, many analogues of acetylacetonates are known. Some examples are ], ] (dbaH){{clarify|reason=The abbreviation for dibenzoylmethane is "DBM", not "dbaH". Am I missing something?|date=November 2023}} and ] analogue ]. ] and ] are also used to generate volatile ]es. |
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==Reactions== |
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===Condensations=== |
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Acetylacetone is a versatile bifunctional precursor to heterocycles because both keto groups may undergo ]. For example, condensation with ] produces ]s while condensation with ] provides ]s. Condensation with two aryl- or alkylamines gives ]s, wherein the oxygen atoms in acetylacetone are replaced by NR (R = aryl, alkyl). |
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===Coordination chemistry=== |
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{{main article|Metal acetylacetonates}} |
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] of VO(acac)<sub>2</sub>]] |
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], Na(acac), is the precursor to many ]es. A general method of synthesis is to treat a metal salt with acetylacetone in the presence of a ]:<ref>{{cite web|url=http://homepages.gac.edu/~bobrien/Inorganic_Lab/acac/Co.tfa.3.&.Co.acac.3.handout.S01.pdf|title=Co(tfa)<sub>3</sub> & Co(acac)<sub>3</sub> handout|first=Brian|last= O'Brien|publisher= Gustavus Adolphus College}}</ref> |
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:{{chem2|MB_{''z''} + ''z'' Hacac <-> M(acac)_{''z''} + ''z'' BH}} |
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Both oxygen atoms bind to the metal to form a six-membered chelate ring. In some cases the ] is so strong that no added base is needed to form the complex. |
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==Biodegradation== |
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The enzyme ] cleaves a central carbon-carbon bond of acetylacetone, producing acetate and ]. The enzyme is ]-dependent, but it has been proven to bind to ] as well. Acetylacetone degradation has been characterized in the bacterium '']''.<ref>{{cite journal|last1=Straganz|first1=G.D.|last2=Glieder|first2=A.|last3=Brecker|first3=L.|last4=Ribbons|first4=D.W.|last5=Steiner|first5=W.|year=2003|title=Acetylacetone-cleaving enzyme Dke1: a novel C–C-bond-cleaving enzyme from'' Acinetobacter johnsonii''|journal= Biochemical Journal|pmid=12379146|volume=369|issue=3|pmc=1223103|pages=573–581|doi=10.1042/BJ20021047}}</ref> |
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:{{chem2|CH3C(O)CH2C(O)CH3 + ] → ] + ]}} |
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==References== |
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{{Reflist}} |
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==External links== |
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*{{ICSC|0533|05}} |
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{{Acetylacetonate complexes}} |
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] |
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] |
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] |