楔形烷

楔形烷
	IUPAC名; Pentacyclo[3.3.0.0 2,4.03,7.06,8]octane; 五環[3.3.0.0 2,4.03,7.06,8]辛烷
識別
CAS號	20656-23-9
PubChem	140734; 54749138（2R,4R,6R,8R）; 11194301（2S,4S,6S,8S）
ChemSpider	124127
SMILES	C12C3C4C3C3C1C2C43;
性質
化學式	C8H8
摩爾質量	104.06 g·mol⁻¹
密度	1.578 g/ml
熔點	-22.19°C
沸點	137.895°C
危險性
閃點	7.646°C
	若非註明，所有數據均出自標準狀態（25 ℃，100 kPa）下。

楔形烷（英語：Cuneane）是一種飽和的環烷烴，化學式為C₈H₈。其英文名由拉丁文「cuneus」衍生，意為「楔子」。^[1]

楔形烷是立方烷的價鍵異構體^[2]。楔形烷的衍生物中，某些還具有液晶的性質^[3]。

八甲基楔形烷比較穩定^[2]。

製備[編輯]

楔形烷可以由立方烷經由金屬離子催化的σ遷移反應來製備^[4]^[5]，如Ag⁺與Pd²⁺均可催化此反應；直接加熱亦可^[2]。該反應是一個放熱反應^[6]，因為楔形烷的張力能比立方烷小^[2]。同樣的反應也發生在高立方烷（C₉H₁₀）以及雙高立方烷（C₁₀H₁₀）上。^[7]^[8]

幾何特性[編輯]

在楔形烷中存在着三組化學環境相同的碳原子（下圖中的A，B，C），這也已經被NMR方法所證實^[9] 。化學環境相同的氫原子也有三組^[2]。楔形烷的碳骨架的分子圖是一個正則圖，並具有三組不等效的頂點。因此它也是數學化學（英語：Mathematical chemistry）中重要的測試不同算法的測試物。^[10]^[11]

類似的幾何結構還出現在其他化合物中。如[Ni₈(L^14Naph)₁₂](BF₄)₁₆這一配合物中，陽離子中的8個鎳原子的相對位置就與楔形烷中碳原子的空間位置相同。^[12]

參見[編輯]

參考資料[編輯]

^ R. Criegee, R. Askani. Octamethylsemibullvalene. Angewandte Chemie International Edition in English. 1968, 7 (7): 537. doi:10.1002/anie.196805371.
^ ^2.0 ^2.1 ^2.2 ^2.3 ^2.4 薛價猷. (CH)_n多面体烷的合成与结构. 化學通報. 1985, (2): 31－39.
^ Bényei, Gyula; Jalsovszky, István; Demus, Dietrich; Prasad, Krishna; Rao, Shankar; Vajda, Anikó; Jákli, Antal; Fodor‐Csorba, Katalin. First liquid crystalline cuneane‐caged derivatives: a structure-property relationship study. Liquid Crystals. 2006, 33 (6): 689–696. doi:10.1080/02678290600722940.
^ Michael B. Smith, Jerry March. March’s Advanced Organic Chemistry 5th. John Wiley & Sons, Inc. 2001: 1459. ISBN 0-471-58589-0.
^ Philip E. Eaton, Luigi Cassar, Jack Halpern. Silver(I)- and palladium(II)-catalyzed isomerizations of cubane. Synthesis and characterization of cuneane. Journal of the American Chemical Society. 1970, 92 (21): 6366–6368. doi:10.1021/ja00724a061.
^ Maria Victoria Roux，Juan Z. Da´valos. Cubane, Cuneane, and Their Carboxylates: A Calorimetric Crystallographic, Calculational, and Conceptual Coinvestigation. J. Org. Chem. 2005. doi:10.1021/jo00408a041.
^ Leo A. Paquette and John C. Stowell. Silver ion catalyzed rearrangements of strained .sigma. bonds. Application to the homocubyl and 1,1'-bishomocubyl systems. Journal of the American Chemical Society. 1970, 92 (8): 2584–2586. doi:10.1021/ja00711a082.
^ W. G. Dauben, M. G. Buzzolini, C. H. Schallhorn, D. L. Whalen, K. J. Palmer. Thermal and silver ion catalyzed isomerization of the 1,1′-bishomocubane system: preparation of a new C₁₀H₁₀isomer. Tetrahedron Letters. 1970, 11 (10): 787–790. doi:10.1016/S0040-4039(01)97830-X.
^ H. Guenther and W. Herrig. Anwendungen der ¹³C-Resonanz-Spektroskopie, X. ¹³C,¹³C-Kopplungskonstanten in Methylencycloalkanen. Chemische Berichte. 1973, 106 (12): 3938–3950. doi:10.1002/cber.19731061217.
^ M.I. Trofimov, E.A. Smolenskii. Electronegativity of atoms of ring-containing molecules—NMR spectroscopy data correlations: a description within the framework of topological index approach. Russian Chemical Bulletin. 2000, 49 (3): 402. doi:10.1007/BF02494766.
^ M.I. Trofimov, E.A. Smolenskii. Application of the electronegativity indices of organic molecules to tasks of chemical informatics. Russian Chemical Bulletin. 2005, 54 (9): 2235. doi:10.1007/s11172-006-0105-6.
^ Stephenson, Andrew; Michael D. Ward. An octanuclear coordination cage with a ‘cuneane’ core—a topological isomer of a cubic cage. Dalton Transactions. 2011, (40). doi:10.1039/C0DT01767A.

外部連結[編輯]

2D and 3D Models of Dodecahedrane and Cuneane Assemblies Link

[1] R. Criegee, R. Askani. Octamethylsemibullvalene. Angewandte Chemie International Edition in English. 1968, 7 (7): 537. doi:10.1002/anie.196805371.

[CHn-2] 2.0 ^2.1 ^2.2 ^2.3 ^2.4 薛價猷. (CH)_n多面体烷的合成与结构. 化學通報. 1985, (2): 31－39.

[3] Bényei, Gyula; Jalsovszky, István; Demus, Dietrich; Prasad, Krishna; Rao, Shankar; Vajda, Anikó; Jákli, Antal; Fodor‐Csorba, Katalin. First liquid crystalline cuneane‐caged derivatives: a structure-property relationship study. Liquid Crystals. 2006, 33 (6): 689–696. doi:10.1080/02678290600722940.

[4] Michael B. Smith, Jerry March. March’s Advanced Organic Chemistry 5th. John Wiley & Sons, Inc. 2001: 1459. ISBN 0-471-58589-0.

[5] Philip E. Eaton, Luigi Cassar, Jack Halpern. Silver(I)- and palladium(II)-catalyzed isomerizations of cubane. Synthesis and characterization of cuneane. Journal of the American Chemical Society. 1970, 92 (21): 6366–6368. doi:10.1021/ja00724a061.

[6] Maria Victoria Roux，Juan Z. Da´valos. Cubane, Cuneane, and Their Carboxylates: A Calorimetric Crystallographic, Calculational, and Conceptual Coinvestigation. J. Org. Chem. 2005. doi:10.1021/jo00408a041.

[7] Leo A. Paquette and John C. Stowell. Silver ion catalyzed rearrangements of strained .sigma. bonds. Application to the homocubyl and 1,1'-bishomocubyl systems. Journal of the American Chemical Society. 1970, 92 (8): 2584–2586. doi:10.1021/ja00711a082.

[8] W. G. Dauben, M. G. Buzzolini, C. H. Schallhorn, D. L. Whalen, K. J. Palmer. Thermal and silver ion catalyzed isomerization of the 1,1′-bishomocubane system: preparation of a new C₁₀H₁₀isomer. Tetrahedron Letters. 1970, 11 (10): 787–790. doi:10.1016/S0040-4039(01)97830-X.

[9] H. Guenther and W. Herrig. Anwendungen der ¹³C-Resonanz-Spektroskopie, X. ¹³C,¹³C-Kopplungskonstanten in Methylencycloalkanen. Chemische Berichte. 1973, 106 (12): 3938–3950. doi:10.1002/cber.19731061217.

[10] M.I. Trofimov, E.A. Smolenskii. Electronegativity of atoms of ring-containing molecules—NMR spectroscopy data correlations: a description within the framework of topological index approach. Russian Chemical Bulletin. 2000, 49 (3): 402. doi:10.1007/BF02494766.

[11] M.I. Trofimov, E.A. Smolenskii. Application of the electronegativity indices of organic molecules to tasks of chemical informatics. Russian Chemical Bulletin. 2005, 54 (9): 2235. doi:10.1007/s11172-006-0105-6.

[12] Stephenson, Andrew; Michael D. Ward. An octanuclear coordination cage with a ‘cuneane’ core—a topological isomer of a cubic cage. Dalton Transactions. 2011, (40). doi:10.1039/C0DT01767A.

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