Skip to Main Content
Conformational analysis and dipole moments of tetra-O-methyl-(+)-catechin and tetra-O-methyl_(-)-epicatechinAuthor(s): W.L. Mattice; F.L. Tobiason; K. Houghlum; A. Shanafelt
Source: Journal of the American Chemical Society 104:3359-3362
Publication Series: Miscellaneous Publication
PDF: View PDF (527 KB)
DescriptionA 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.
- You may send email to firstname.lastname@example.org 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.
CitationMattice, 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
- Crystal structure, conformational analysis, and molecular dynamics of tetra-0-methyl-(+)-catechin
- Dipole moment, solution, and solid state structure (-)-epicatechin, a monomer unit of procyanidin polymers
- Predicting heterocyclic ring coupling constants through a conformational search of tetra-O-methyl-(+)-catechin
XML: View XML