楔形烷

楔形烷
	IUPAC名; Pentacyclo[3.3.0.0 2,4.03,7.06,8]octane; 五环[3.3.0.0 2,4.03,7.06,8]辛烷
识别
CAS号	20656-23-9
PubChem	140734; 54749138（2R,4R,6R,8R）; 11194301（2S,4S,6S,8S）
ChemSpider	124127
SMILES	C12C3C4C3C3C1C2C43;
性质
化学式	C8H8
摩尔质量	104.06 g·mol⁻¹
密度	1.578 g/ml
熔点	-22.19°C
沸点	137.895°C
危险性
闪点	7.646°C
	若非注明，所有数据均出自标准状态（25 ℃，100 kPa）下。

楔形烷（英语：Cuneane）是一种饱和的环烷烃，化学式为C₈H₈。其英文名由拉丁文“cuneus”衍生，意为“楔子”。^[1]

楔形烷是立方烷的价键异构体^[2]。楔形烷的衍生物中，某些还具有液晶的性质^[3]。

八甲基楔形烷比较稳定^[2]。

制备

楔形烷可以由立方烷经由金属离子催化的σ迁移反应来制备^[4]^[5]，如Ag⁺与Pd²⁺均可催化此反应；直接加热亦可^[2]。该反应是一个放热反应^[6]，因为楔形烷的张力能比立方烷小^[2]。同样的反应也发生在高立方烷（C₉H₁₀）以及双高立方烷（C₁₀H₁₀）上。^[7]^[8]

几何特性

在楔形烷中存在着三组化学环境相同的碳原子（下图中的A，B，C），这也已经被NMR方法所证实^[9] 。化学环境相同的氢原子也有三组^[2]。楔形烷的碳骨架的分子图是一个正则图，并具有三组不等效的顶点。因此它也是数学化学（英语：Mathematical chemistry）中重要的测试不同算法的测试物。^[10]^[11]

类似的几何结构还出现在其他化合物中。如[Ni₈(L^14Naph)₁₂](BF₄)₁₆这一配合物中，阳离子中的8个镍原子的相对位置就与楔形烷中碳原子的空间位置相同。^[12]

参见

参考资料

^ 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 薛价猷. (CH)_n多面体烷的合成与结构. 化学通报. 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.

外部链接

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 薛价猷. (CH)_n多面体烷的合成与结构. 化学通报. 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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