Elsevier

Tetrahedron

Volume 28, Issue 6, 1972, Pages 1803-1810
Tetrahedron

Conformational studies on hexahelicenes—I: The NMR spectra of the benzohexahelicenes

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Abstract

The NMR spectra of the benzohexahelicenes have been analyzed. The conformation of the helical structure is not changed to a large extent by the benzo-groups. Some flattening of a part of the helix results in a small downfield shift of the protons on the terminal rings and in a larger upfield shift of proton A in II ascribed to a change in the ring current in the pitch of the helix. A gradual upfield shift is found for protons of the terminal rings by an increase in overcrowding of the benzo-groups.

References (10)

  • R.H. Martin et al.

    Tetrahedron

    (1969)
  • W.H. Laarhoven et al.

    Tetrahedron

    (1970)
  • W.H. Laarhoven et al.

    J. Chem. Soc. B

    (1971)
  • H.J. Bernstein et al.

    Proc. Roy. Soc.

    (1956)
  • C.W. Haigh et al.

    Mol. Phys.

    (1970)
There are more references available in the full text version of this article.

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