Trifluoromethyl Chlorosulfonate, CF3OSO2Cl:  Gas Phase and Crystal Structure, Conformation and Vibrational Analysis Studied by Experimental and Theoretical Methods

• Published in: Inorganic chemistry 2003-11, Vol.42 (22), p.7297-7303
• Main Authors: Erben, Mauricio F, Della Védova, Carlos O, Boese, Roland, Willner, Helge, Leibold, Christiane, Oberhammer, Heinz
• Format: Article
• Language: English
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/ic034531a

The geometric structure and conformational properties of trifluoromethyl chlorosulfonate (chlorosulfuric acid trifluoromethyl ester), CF3OSO2Cl, have been determined by X-ray crystallography, gas electron diffraction (GED), and vibrational spectroscopy (IR(gas), IR(matrix), and Raman(liquid)). These experimental investigations were supplemented by quantum chemical calculations (B3LYP with 6-311G* and 6-311+G(3df) basis sets). All experimental methods result in a single conformer with gauche orientation of the CF3 group relative to the S−Cl bond. The dihedral angle δ(COSCl) is determined to be 91.7(3)° in the crystal and 94(3)° in the gas phase. This dihedral angle corresponds to a near-eclipsed orientation of the OC bond relative to one of the SO double bonds (δ(COSO) = −23.0(3)° and −21(3)° in the crystal and gas phase, respectively).