The effects of conformational variations on the packing of cup shaped molecules

COMP 268

Michael Roumanos, roumanos@gmail.com, Miklos Kertesz, kertesz@georgetown.edu, and K. Travis Holman, kth7@georgetown.edu. Department of Chemistry, Georgetown University, Washington, DC 20057-1227
Crystallographic studies have shown that cup-shaped cyclotriveratrylene (CTV, CSD refcode: CUVHAC01) molecules assume geometries that do not maximize symmetry by deviating from the C3v point group and forming jagged stacks1. The constituent methoxy groups in the crystal also align in directions that do not correspond to the lowest energy conformation obtained by density functional theory for an isolated molecule. These counterintuitive conformations are expected to be results of local dipoles, dispersion forces, electron distribution, and angle strains. In this study, we monitor these properties and evaluate how each affects the packing structure. Adjustments will then be made to develop an optimized molecular crystal structure with the lowest energy conformation. The packing preferences obtained in this analysis will be used to attempt the interpretation of several CTV structures used as container molecules.

1Zhang, H.; Atwood, J. L. J. Cryst. Spect. Res. 1990, 20, 465.

 

Poster Session
6:00 PM-8:00 PM, Tuesday, August 18, 2009 Walter E. Washington Convention Center -- Ballroom A, Poster

Division of Computers in Chemistry

The 238th ACS National Meeting, Washington, DC, August 16-20, 2009