Skip to Main Content
U.S. Forest Service
Caring for the land and serving people

United States Department of Agriculture

Home > Search > Publication Information

  1. Share via EmailShare on FacebookShare on LinkedInShare on Twitter
    Dislike this pubLike this pub
    Author(s): W.L. Mattice; F.L. Tobiason; K. Houghlum; A. Shanafelt
    Date: 1982
    Source: Journal of the American Chemical Society 104:3359-3362
    Publication Series: Miscellaneous Publication
    PDF: View PDF  (527 KB)

    Description

    A conformational energy analysis has been performed for tetra-0-methyl-(+)-catechin and tetra-O-methyl-(-)-epicatechin. Rotation was permitted about five C-O bonds and about the single bond connecting two rings. Eighteen rotational isomers each were assigned for tetra-0-methyl-(-)-epicatechin. Relative populations of the rotational isomers are governed by short-range interactions which give rise to five weighting factors, one of which is common to tetra-0-methyl-(+)-catechin and tetra-0-methyl-(-)-epicatechin. The mean-square dipole moment is most sensitive to the weighting factor common to the two molecules studied. The calculated root-mean-square dipole moment of tetra-0-methyl-(-)-epicatechin at 300 K is in excellent agreement with the experimental value of 2.98 D obtained in p-dioxane. In the case of tetra-0-methyl-(+)-catechin, the calculated root-mean-square dipole moment is larger than the experimental result of 2.45 D if ring conformations in solution are the same as those found in the crystal. Good agreement between theory and experiment for tetra-0-methyl-(+)-catechin can be obtained if an alternative ring conformation is assumed. Temperature coefficients were calculated and found experimentally to be positive for both molecules.

    Publication Notes

    • You may send email to pubrequest@fs.fed.us to request a hard copy of this publication.
    • (Please specify exactly which publication you are requesting and your mailing address.)
    • We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
    • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.

    Citation

    Mattice, W.L.; Tobiason, F.L.; Houghlum, K.; Shanafelt, A. 1982. Conformational analysis and dipole moments of tetra-O-methyl-(+)-catechin and tetra-O-methyl_(-)-epicatechin. Journal of the American Chemical Society 104:3359-3362

    Related Search


    XML: View XML
Show More
Show Fewer
Jump to Top of Page