title: Conformational Study of trans-Cyclododecene by Dynamic NMR Spectroscopy and Computational Methods.
abstract: The (13)C spectrum of trans-cyclododecene (1) dissolved in propane showed seven peaks for the olefinic carbons at -164.5 degrees C, corresponding to three conformations of C(1) symmetry and a fourth conformation, with a population of 20.1%, of C(2) symmetry. The populations of the C(1) conformations were 57.0, 18.6, and 4.3%. Conformational space was searched for 1 using MM2. Free energies and populations were calculated by MM3, and the results of the low-temperature NMR study are discussed in terms of these calculations and the (13)C chemical shifts calculated for eight conformations by the GIAO method at the HF/6-311G level. The conformations of 1 and cyclododecane (2) are compared.
authors.affiliation: Department of Chemistry, Jackson State University, Jackson, Mississippi 39217-0510.
authors.forename: Diwakar M.
authors.initials: DM
authors.lastname: Pawar
authors.forename: Kristie L.
authors.initials: KL
authors.lastname: Davis
authors.forename: Bennie L.
authors.initials: BL
authors.lastname: Brown
authors.forename: Sumona V.
authors.initials: SV
authors.lastname: Smith
authors.forename: Eric A.
authors.initials: EA
authors.lastname: Noe