title: A conformational and vibrational study of CF(3)COSCH(2)CH(3).
abstract: The molecular structure and conformational properties of S-ethyl trifluorothioacetate, CF(3)COSCH(2)CH(3), were determined in the gas phase by electron diffraction and vibrational spectroscopy (IR and Raman). The experimental investigations were supplemented by ab initio (Moller Plesset of second order) and density functional theory quantum chemical calculations at different levels of theory. Both experimental and theoretical methods reveal two structures with C(s) (anti, anti) and C(1) (anti, gauche) symmetries, although there are disagreements about which is more stable. The electron diffraction intensities are best interpreted with a mixture of 51(3)% anti, anti and 49(3)% anti, gauche conformers. This conformational preference was studied using the total energy scheme and the natural bond orbital scheme. In addition, the infrared spectra of CF(3)COSCH(2)CH(3) are reported for the gas, liquid and solid phases as well as the Raman spectrum of the liquid. Using calculated frequencies as a guide, evidence for both C(s) and C(1) structures is obtained in the IR spectra. Harmonic vibrational frequencies and scaled force fields have been calculated for both conformers.
authors.affiliation: Instituto de Química del Noroeste Argentino (INQUINOA), Consejo Nacional de Investigaciones Cientificas y Técnicas (CONICET), Argentina.
authors.forename: María Eliana Defonsi
authors.initials: ME
authors.lastname: Lestard
authors.forename: María Eugenia
authors.initials: ME
authors.lastname: Tuttolomondo
authors.forename: Derek A
authors.initials: DA
authors.lastname: Wann
authors.forename: Heather E
authors.initials: HE
authors.lastname: Robertson
authors.forename: David W H
authors.initials: DW
authors.lastname: Rankin
authors.forename: Aida
authors.initials: A
authors.lastname: Ben Altabef
mesh_terms: D005463:Fluoroacetates; D008958:Models, Molecular; D008968:Molecular Conformation; D011789:Quantum Theory; D013055:Spectrophotometry, Infrared; D013059:Spectrum Analysis, Raman; D014269:Trifluoroacetic Acid / Q000737:chemistry
chemical_list: D005463:Fluoroacetates; C028085:ethylthiol trifluoroacetate; D014269:Trifluoroacetic Acid