ORGN 301 |
| Eric A. Noe, Arnaldo E. Marrero, Dalephine Davis, Judge Brown II, and Diwakar M Pawar. Department of Chemistry, Jackson State University, 1400 J. R. Lynch Street, Jackson, MS 39217-0510 |
| The 13C spectrum of a 1% solution of cyclopentadecane in propane showed the presence of 8 overlapping peaks at -170°C (dial temperature), although the actual number is uncertain because of a low signal-to-noise ratio and a small range of chemical shifts. The peaks could be consistent with a conformation of C2 symmetry, but the possibility of additional conformations cannot be excluded. The carbon NMR spectra were analyzed in terms of the conformations predicted by Allinger's molecular mechanics program, which indicated that a conformation of C2 symmetry is of lowest strain energy and is more stable than the next (C1) conformation by 0.32 kcal/mol. The free energies for the first ten conformations were obtained at the HF/6-311G* level and compared with the MM3 results; calculations for -180°C predict four conformations with relative free energies within 0.35 kcal/mol, and with two each of C1 and C2 symmetries. |
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Physical Organic, Combinatorial, Materials, Molecular Recognition
8:00 PM-10:00 PM, Tuesday, March 30, 2004 Anaheim Convention Center -- Hall A, Poster
Division of Organic Chemistry |