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dc.creatorTrue, Nancy S.en_US
dc.creatorBohn, Robert K.en_US
dc.date.accessioned2006-06-15T13:39:21Z
dc.date.available2006-06-15T13:39:21Z
dc.date.issued1975en_US
dc.identifier1975-RG-06en_US
dc.identifier.urihttp://hdl.handle.net/1811/9375
dc.descriptionAuthor Institution: Department of Chemistry and Institute of Materials Science, University of Connecticuten_US
dc.description.abstractLow resolution microwave spectra of ethyl trifluoroacetate display three a-type band series characterized by $B + C$ values of $1842 \pm 2$ MHz, $1947 \pm 2$ MHz, and $1910 \pm 6$ MHz associated with three rotameric forms designated extended, compact, and intermediate, respectively. Ethyl cyanoformate and ethyl chloroformate also display band spectra of three conformations with $B + C$ values of $2752 \pm 2$ MHz, $2954 \pm 3$ KHz, and $2870 \pm 2$ MHz for the cyanoformate and $2819 \pm 3$ MHz ($2762 \pm 3$ MHz, $^{37}Cl$), $3061 \pm 3 MHz$ ($2989 \pm 3$ MHz, $^{37}Cl$), and $2954 \pm 5$ MHz ($2885 \pm 17$ MHz, $^{37}Cl$) for the chloroformate. For each compound the rotational constants of the extended species are consistent with a cis-trans[$\tau(O=COC = 0^{\circ}$, $\tau(COCC) = 180^{\circ}$] heavy atom planar structure, the compact species with a cis-gauche[$\tau(O=COC) = 0^{\circ}$, $\tau(COCC) \sim 90^{\circ}$] structure, and the intermediate species with a gauche-gauche[$\tau(O=COC) \sim 50^{\circ}$, $^{\circ}(COCC) \sim 21^{\circ}$ structure. The cis-trans and cis-gauche structures have been identified in ethyl formate by Riveros and Wilson. (J. Chem. Phys. 42, 4605 (1967)). From the temperature dependence of the band Intensities, the relative energies of the extended, compact, and intermediate species are $0, 0, 1 \pm 0.2$, and $2.0 \pm 0.2$ kcal/mole for ethyl trifluoroacetate; $0, 0.1 \pm 0.2$, and $1.4 \pm 0.4$ kcal/mole for ethyl cyanoformate; and $0, 0 \pm 0.1$, and $1.2 \pm 0.5$ kcal/mole for ethyl chloroformate.en_US
dc.format.extent180753 bytes
dc.format.mimetypeimage/jpeg
dc.language.isoEnglishen_US
dc.publisherOhio State Universityen_US
dc.titleLOW RESOLUTION MICROWAVE SPECTROSCOPY AND THE THREE CONFORMERS OF ETHYL TRIFLUOROACETATE, ETHYL CYANOFORMATE AND ETHYL CHLOROFORMATEen_US
dc.typearticleen_US


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