Structural Chemistry

, Volume 5, Issue 5, pp 335–340 | Cite as

Aryl ring twists in tris(2,6-dimethoxyphenyl)-z tripod ethers: X-ray analysis of an isostructural series of triarylpropellers

  • Scott J. Stoudt
  • Prakash Gopalan
  • Bart Kahr
  • James E. Jackson


Tris(2,6-dimethoxyphenyl)amine has been synthesized and its molecular and crystal structure determined by X-ray diffraction. This structure completes the series of isosteric compounds Ar3Z, where Z=B, C., N, and Ar=2,6-dimethoxyphenyl. Structures for the tris(2-methoxy-6-methylphenyl) borane and tris(2,6-dimethoxyphenyl)methyl cation triiodide (Ar3C+I3) are also reported. The Ar3B and Ar3N structures are isomorphous. The triiodide and the earlier reported tetrafluoroborate salt (Ar3C+BF4) are also quite similar, as are the two boranes above and the known trimesitylborane, which all tend toward D3 symmetric conformations. In contrast, the radical Ar3C., intermediate between Ar3B and Ar3N, is markedly unsymmetrical. Taken together, these findings support an earlier conjecture that the solid-state conformation of Ar3C. does not represent a minimum energy structure for the free radical in solution. Crystal seeding by radical oxidation products is offered as an explanation for the radical's markedly unsymmetrical crystal geometry.

Key words

Tripod ethers triarylpropellers triarylamine triarylborane triarylmethyl radical 


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Copyright information

© Plenum Publishing Corporation 1994

Authors and Affiliations

  • Scott J. Stoudt
    • 1
  • Prakash Gopalan
    • 2
  • Bart Kahr
    • 2
  • James E. Jackson
    • 1
    • 3
  1. 1.Department of Chemistry and Center for Fundamental Materials ResearchMichigan State UniversityEast Lansing
  2. 2.Dept. of ChemistryPurdue UniversityWest Lafayette
  3. 3.Dept. of ChemistryMichigan State UniversityEast Lansing

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