Cuneane

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Cuneane (C8H8, Pentacyclo[3.3.0.0 2,4.03,7.06,8]octane) saturated hydrocarbon with 3D-structure (however molecular graph of cuneane is a planar graph). Its name was derived from the Latin “cuneus”, meaning a wedge.[1] Cuneane may be produced from cubane by metal-ion-catalyzed σ-bond rearrangement.[2][3] Similar reactions are known for homocubane (C9H10) and bishomocubane (C10H10).[4][5]

Scheme 1. Synthesis of cuneane from cubane

The cuneane molecule has three groups of equivalent carbon atoms (A, B, C), which had been also confirmed by NMR.[6] The molecular graph of carbon sceletion of cuneane is regular graph with non-equivalent groups of vertices, and so it is very important test object for different algorithms of mathematical chemistry.[7][8]

Scheme 2. Equivalent carbon atoms in cuneane

Some cuneane derivatives have liquid crystals properties.[9]

[edit] References

  1. ^ R. Criegee, R. Askani (1968). "Octamethylsemibullvalene". Angewandte Chemie International Edition in English 7 (7): 537. doi:10.1002/anie.196805371. 
  2. ^ Michael B. Smith, Jerry March (2001). March’s Advanced Organic Chemistry, 5th Ed, John Wiley & Sons, Inc., 1459. ISBN 0-471-58589-0. 
  3. ^ Philip E. Eaton, Luigi Cassar, Jack Halpern (1970). "Silver(I)- and palladium(II)-catalyzed isomerizations of cubane. Synthesis and characterization of cuneane". Journal of the American Chemical Society 92 (21): 6366-6368. doi:10.1021/ja00724a061. 
  4. ^ Leo A. Paquette and John C. Stowell (1970). "Silver ion catalyzed rearrangements of strained .sigma. bonds. Application to the homocubyl and 1,1'-bishomocubyl systems". Journal of the American Chemical Society 92 (8): 2584 - 2586. doi:10.1021/ja00711a082. 
  5. ^ W. G. Dauben, M. G. Buzzolini, C. H. Schallhorn, D. L. Whalen, K. J. Palmer (1970). "Thermal and silver ion catalyzed isomerization of the 1,1′-bishomocubane system: preparation of a new C10H10isomer". Tetrahedron Letters 11 (10): 787-790. doi:10.1016/S0040-4039(01)97830-X. 
  6. ^ H. Guenther and W. Herrig (1973). "Anwendungen der 13C-Resonanz-Spektroskopie, X. 13C,13C-Kopplungskonstanten in Methylencycloalkanen". Chemische Berichte 106: 3938-3950. doi:10.1002/cber.19731061217. 
  7. ^ M.I. Trofimov, E.A. Smolenskii (2000). "Electronegativity of atoms of ring-containing molecules—NMR spectroscopy data correlations: a description within the framework of topological index approach". Russian Chemical Bulletin 49 (3): 402. doi:10.1007/BF02494766. 
  8. ^ M.I. Trofimov, E.A. Smolenskii (2005). "Application of the electronegativity indices of organic molecules to tasks of chemical informatics". Russian Chemical Bulletin 54 (9): 2235. doi:10.1007/s11172-006-0105-6. 
  9. ^ Bényei, Gyula; Jalsovszky, István; Demus, Dietrich; Prasad, Krishna; Rao, Shankar; Vajda, Anikó; Jákli, Antal; Fodor‐Csorba, Katalin (2006). "First liquid crystalline cuneane‐caged derivatives: a structure-property relationship study". Liquid Crystals 33 (6): 689-696. doi:10.1080/02678290600722940.