| Revision as of 15:38, 6 December 2011 editBeetstra (talk | contribs)Edit filter managers, Administrators172,031 edits Saving copy of the {{chembox}} taken from revid 454134135 of page Sodium_ethoxide for the Chem/Drugbox validation project (updated: ''). |
Latest revision as of 07:20, 9 August 2024 edit WikiCleanerBot (talk | contribs)Bots925,164 editsm v2.05b - Bot T20 CW#61 - Fix errors for CW project (Reference before punctuation)Tag: WPCleaner |
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{{Short description|Ionic compound made of a C2H5–O anion and a sodium cation}} |
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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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| verifiedrevid = 444967070 |
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| ImageFile = sodium_ethoxide.png |
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| verifiedrevid = 464401325 |
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| ImageFileL1 = Ethoxide-3D-balls.png |
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| ImageFile = Sodium ethoxide.svg |
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| ImageSizeL1 = 150px |
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| ImageSize = 200px |
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| ImageNameL1 = Ball-and-stick model of the ethoxide anion |
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| ImageName = Ball-and-stick model of the sodium cation |
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| ImageFileR1 = Sodium-3D.png |
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| ImageFile1 = Sodium-ethoxide-xtal-layer-view-1-Mercury-3D-bs.png |
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| ImageSizeR1 = 85px |
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| OtherNames = Sodium ethanolate, sodium ethylate (''obsolete'') |
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| ImageNameR1 = Ball-and-stick model of the sodium cation |
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|Section1={{Chembox Identifiers |
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| IUPACName = Sodium ethoxide |
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| Section1 = {{Chembox Identifiers |
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| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} |
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| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} |
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| ChemSpiderID = 8516 |
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| ChemSpiderID = 8516 |
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| CASNo_Ref = {{cascite|correct|CAS}} |
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| CASNo_Ref = {{cascite|correct|CAS}} |
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| CASNo = 141-52-6 |
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| CASNo = 141-52-6 |
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| PubChem = 2723922 |
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}} |
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| EC_number = 205-487-5 |
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| Section2 = {{Chembox Properties |
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| UNII = 1I9504387J |
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| Formula = C<sub>2</sub>H<sub>5</sub>ONa |
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| DTXSID = DTXSID3027089 |
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| MolarMass = 68.05 g/mol |
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| Density = 0.868 g/cm^3 |
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| ChEBI = 52096 |
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| Beilstein = 3593646 |
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| Appearance = white powder <br> ] |
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}} |
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| Solubility = Reacts violently with water (] with ] and ]) |
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|Section2={{Chembox Properties |
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| Formula = {{chem2|CH3CH2ONa}} |
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| C=2|H=5|O=1|Na=1 |
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| Density = 0.868 g/cm<sup>3</sup> (of a 21 wt% solution in ethanol) |
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| Appearance = White ] powder |
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| Solubility = Reacts |
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| SolubleOther = ] and ] |
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| MeltingPtC = 260 |
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| MeltingPtC = 260 |
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| pKa = 15.5<ref>disassociation constant of Ethanol, referenced in the CRC Handbook of Chemistry and Physics 87th edition.</ref> |
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| pKa = 15.5<ref>disassociation constant of ethanol, referenced in the CRC Handbook of Chemistry and Physics 87th edition.</ref> |
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| Section7 = {{Chembox Hazards |
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|Section7={{Chembox Hazards |
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| FlashPt = |
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| NFPA-H = 2 |
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| NFPA-H = 2 |
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| NFPA-F = 2 |
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| NFPA-F = 2 |
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| NFPA-R = 1 |
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| NFPA-R = 1 |
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| NFPA-O = W |
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| NFPA-S = W |
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| ExternalMSDS = |
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| ExternalSDS = |
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| EUClass = {{Hazchem F+}} {{Hazchem Xn}} {{Hazchem C}} |
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| GHSPictograms = {{GHS02}}{{GHS05}}{{GHS07}} |
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| GHSSignalWord = Danger |
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}} |
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| HPhrases = {{H-phrases|228|251|302|314}} |
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| PPhrases = {{P-phrases|210|235+410|240|241|260|264|270|280|301+312|301+330+331|303+361+353|304+340|305+351+338|310|321|330|363|370+378|405|407|413|420|501}} |
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'''Sodium ethoxide,''' also referred to as '''sodium ethanolate''', is the ], ] with the formula {{chem2|CH3CH2ONa}}, {{chem2|C2H5ONa|auto=1}}, or NaOEt (Et = ]). It is a white solid, although impure samples appear yellow or brown. It dissolves in polar solvents such as ]. It is commonly used as a strong ].<ref>{{cite encyclopedia |author1=K. Sinclair Whitaker |author2=D. Todd Whitaker |editor-last=Charette |editor-first=André B. |encyclopedia=Encyclopedia of Reagents for Organic Synthesis |title=Sodium Ethoxide |date=2001 |publisher=] |isbn=978-0-470-84289-8 |doi=10.1002/047084289X.rs070}}</ref> |
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==Preparation== |
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Few procedures have been reported to prepare the anhydrous solid. Instead the material is typically prepared in a solution with ethanol. It is commercially available and as a solution in ethanol. It is easily prepared in the laboratory by treating ] metal with absolute ]:<ref name=OS>{{OrgSynth|author=C. S. Marvel, E. E. Dreger|year=1926|title=Ethyl Acetopyruvate|volume=6|page=40|doi=10.15227/orgsyn.006.0040}}</ref> |
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:{{chem2|2 CH3CH2OH + 2 Na → 2 CH3CH2ONa + ]}} |
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The reaction of ] with anhydrous ethanol suffers from incomplete conversion to the ethoxide, but can still produce dry NaOEt by precipitation using acetone,<ref>{{Cite patent|number=US1978647A|title=Method for making alkali metal alcoholates|gdate=1934-10-30|invent1=Olson|invent2=Twining|inventor1-first=Edgar T.|inventor2-first=Ralph H.|url=https://patents.google.com/patent/US1978647/en}}</ref> or by drying using additional NaOH.<ref>{{Cite patent|number=US2796443A|title=Method for making anhydrous alkali metal alcoholates|gdate=1957-06-18|invent1=Meyer|invent2=Johnson|inventor1-first=Robert H.|inventor2-first=Arthur K.|url=https://patents.google.com/patent/US2796443/en}}</ref> |
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==Structure== |
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The crystal structure of sodium ethoxide has been determined by ]. It consists of layers of alternating {{chem2|Na+}} and {{chem2|O−}} centres with disordered ]s covering the top and bottom of each layer. The ethyl layers pack back-to-back resulting in a ]. The reaction of sodium and ethanol sometimes forms other products such as the disolvate {{chem2|CH3CH2ONa*2]}}. Its crystal structure has been determined, although the structure of other phases in the {{chem2|CH3CH2ONa/CH3CH2OH}} system remain unknown.<ref>{{cite journal | title = Crystal structure of sodium ethoxide (C<sub>2</sub>H<sub>5</sub>ONa), unravelled after 180 years |author=M. Beske |author2=L. Tapmeyer |author3=M. U. Schmidt | journal = ] | year = 2020 | volume = 56 | issue = 24 | pages = 3520–3523 | doi = 10.1039/C9CC08907A | pmid = 32101200 | s2cid = 211523921}}</ref> |
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{| class="wikitable" style="text-align:center;" |
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|]||]||] |
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|<small>] of layer stacking<br /> in the crystal structure of {{chem2|CH3CH2ONa}}</small>||<small>] at Na</small>||<small>coordination geometry at O</small> |
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==Reactions== |
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Sodium ethoxide is commonly used as a base in the ]<ref name="Clayden-2012">{{cite book |last1=Clayden |first1=Jonathan |last2=Greeves |first2=Nick |last3=Warren |first3=Stuart |title=Organic chemistry |date=2012 |publisher=Oxford University Press |location=New York |isbn=978-0-19-927029-3 |page=645 |edition=2nd}}</ref> and ].<ref name="Wang-2010">{{cite book |last1=Wang |first1=Zerong |title=Comprehensive organic name reactions and reagents |date=15 September 2010 |publisher=John Wiley |isbn=978-0-471-70450-8 |pages=1811–1815}}</ref> Sodium ethoxide may either deprotonate the α-position of an ] molecule, forming an ], or the ester molecule may undergo a ] called ]. If the starting material is an ethyl ester, trans-esterification is irrelevant since the product is identical to the starting material. In practice, the alcohol/alkoxide solvating mixture must match the alkoxy components of the reacting esters to minimize the number of different products. |
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Many ]s are prepared by ] from sodium ethoxide. |
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==Stability== |
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Sodium ethoxide is prone to reaction with both water and ] in the ].<ref name="Wethman Derosa Tran Kang p.2">{{citation|last1=Wethman|first1=Robert|title=An Under-Appreciated Source of Reproducibility Issues in Cross-Coupling: Solid-State Decomposition of Primary Sodium Alkoxides in Air|date=2020-08-19|url=https://figshare.com/articles/preprint/An_Under-Appreciated_Source_of_Reproducibility_Issues_in_Cross-Coupling_Solid-State_Decomposition_of_Primary_Sodium_Alkoxides_in_Air/12818234|publisher=American Chemical Society (ACS)|doi=10.26434/chemrxiv.12818234.v1|last2=Derosa|first2=Joseph|last3=Tran|first3=Van|last4=Kang|first4=Taeho|last5=Apolinar|first5=Omar|last6=Abraham|first6=Anuji|last7=Kleinmans|first7=Roman|last8=Wisniewski|first8=Steven|last9=Coombs|first9=John|last10=Engle|first10=Keary|s2cid=242420220}}</ref> This leads to degradation of stored samples over time, even in solid form. The physical appearance of degraded samples may not be obvious, but samples of sodium ethoxide gradually turn dark on storage. It has been reported that even newly-obtained commercial batches of sodium ethoxide show variable levels of degradation, and responsible as a major source of irreproducibility when used in ]s.<ref name="Wethman Derosa Tran Kang p.2" /><gallery> |
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File:Sodium-ethoxide-reagent-bottle.jpg|New bottle of sodium ethoxide from Sigma-Aldrich |
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File:Sodium-ethoxide-reagent-contents.jpg|Freshly opened container of sodium ethoxide showing discoloration caused by degradation when stored over oxygen and carbon dioxide. |
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</gallery>In moist air, {{chem2|CH3CH2ONa}} ] rapidly to ] (NaOH). The conversion is not obvious and typical samples of {{chem2|CH3CH2ONa}} are contaminated with NaOH. |
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In ]-free air, solid sodium ethoxide can form sodium ethyl carbonate from fixation of carbon dioxide from the air. Further reactions lead to degradation into a variety of other sodium ] and ].<ref name="Wethman Derosa Tran Kang p.2" /> |
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This instability can be prevented by storing sodium ethoxide under an ] (e.g., ]). |
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==Safety== |
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Sodium ethoxide is a strong ], and is therefore corrosive. |
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==See also== |
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* ] |
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* ] |
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* ] |
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* ] |
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* ] |
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* ] |
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==References== |
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{{Reflist}} |
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] |
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