| 词条 | 1,6-Methano(10)annulene |
| 释义 |
| Name = 1,6-Methano[10]annulene | ImageFile = 1,6-methanonaphthalene.svg | ImageSize = 150px | IUPACName = Bicyclo[4.4.1]undeca-1,3,5,7,9-pentaene | OtherNames = | Section1 = {{Chembox Identifiers | CASNo = 2443-46-1 | PubChem = 137603 | ChemSpiderID = 121264 | SMILES = c1ccc2ccccc(c1)C2 | InChI = 1/C11H10/c1-2-6-11-8-4-3-7-10(5-1)9-11/h1-8H,9H2 | InChIKey = OORRQYZWSVJKSO-UHFFFAOYAC | StdInChI = 1S/C11H10/c1-2-6-11-8-4-3-7-10(5-1)9-11/h1-8H,9H2 | StdInChIKey = OORRQYZWSVJKSO-UHFFFAOYSA-N | Section2 = {{Chembox Properties | C=11|H=10 | Appearance = | Density = | MeltingPt = | BoilingPt = | Solubility = | Section3 = {{Chembox Hazards | MainHazards = | FlashPt = | AutoignitionPt = }} 1,6-Methano[10]annulene (also known as 1,6-methanonaphthalene or homonaphthalene) is an aromatic hydrocarbon with chemical formula C{{sub|11}}H{{sub|10}}. It was the first stable aromatic compound based on the cyclodecapentaene system to be discovered. PreparationAccording to Organic Syntheses, it can be prepared from naphthalene.[1] {{clear-left}} AromaticityIt is analogous to cyclodecapentaene ([10]annulene), but with two hydrogen atoms replaced by a transannular methylene bridge ({chem|CH|2}). Consequently, it obeys Hückel's rule (n = 2) and despite the distortion from planarity introduced by the methylene bridge, the compound is aromatic.[3] In fact, when prepared by Vogel in the 1960s[4][5] it was the first stable aromatic cyclodecapentaene to be discovered.[3] [Note: It was later discovered that in actuality, this molecule was first prepared by Heinz D. Roth, who showed the molecule to Vogel, the man who consequently took credit for the work.] Its aromaticity is confirmed by three main pieces of evidence. Firstly, the similarity in carbon-carbon bond lengths as measured by x-ray crystallography is inconsistent with alternating single and double bonds. The actual structure is better considered as a pair of resonance hybrids (like the Kekulé structures of benzene) rather than as having alternating single and double bonds. Secondly, its {{sup|1}}H NMR spectrum displays influence of the diamagnetic ring current which is characteristic of aromatic compounds. The peripheral protons around the ring are deshielded while the methylene bridge nuclei are strongly shielded.[3] Its resonance energy is smaller than that of naphthalene.[9] See also
References1. ^1 2 3 {{cite journal|title = Forfeiture of the aromaticity of a bridged [10]annulene by benzannelation|first1 = Richard K.|last1 = Hill|first2 = Carolyn B.|last2 = Giberson|first3 = James V.|last3 = Silverton|journal = J. Am. Chem. Soc.|year = 1988|volume = 110|issue = 2|pages = 497–500|doi = 10.1021/ja00210a031}} [1][2][3][4][5]2. ^1 {{OrgSynth|title = 1,6-Methano[10]annulene|collvol = 6|collvolpages = 731|volume = 54|pages = 11|doi = 10.15227/orgsyn.054.0011|first1 = Emanuel|last1 = Vogel|first2 = W.|last2 = Klug|first3 = A.|last3 = Breuer|url = http://www.orgsyn.org/demo.aspx?prep=cv6p0731}} 3. ^1 {{cite journal|last1 = Roth|first1 = Wolfgang R.|first2 = Manfred|last2 = Böhm|title = Resonance Energy of Bridged [10]Annulene|journal = Angew. Chem. Int. Ed.|year = 1983|volume = 22|issue = 12|pages = 1007–1008|doi = 10.1002/anie.198310071}} 4. ^1 {{cite journal|last1 = Vogel|first1 = Emanuel|first2 = H. D.|last2 = Roth|title = The Cyclodecapentaene System|journal = Angew. Chem. Int. Ed.|year = 1964|volume = 3|issue = 3|pages = 228–229|doi = 10.1002/anie.196402282}} 5. ^1 {{cite journal|last1 = Vogel|first1 = Emanuel|first2 = W. A.|last2 = Böll|journal = Angew. Chem. Int. Ed.|title = Substitution of 1,6-Methanocyclodecapentaene|year = 1964|volume = 3|issue = 9|page = 642|doi = 10.1002/anie.196406421}} }}{{DEFAULTSORT:Methanoannulene, 1, 6-}} 2 : Aromatic hydrocarbons|Non-benzenoid aromatic carbocycles |
| 随便看 |
|
开放百科全书收录14589846条英语、德语、日语等多语种百科知识，基本涵盖了大多数领域的百科知识，是一部内容自由、开放的电子版国际百科全书。