title: Anomeric effects in sulfonyl compounds: an experimental and computational study of fluorosulfonyl azide, FSO(2)N(3), and trifluoromethylsulfonyl azide, CF(3)SO(2)N(3).
abstract: Fluorosulfonyl azide, FSO(2)N(3), was characterized by IR (gas phase, Ar matrix), and Raman (liquid) spectroscopy. According to the matrix IR spectrum of (18)O-labeled FSO(2)N(3), its two oxygen atoms are nonequivalent. This assumption was confirmed by the X-ray crystal structure of FSO(2)N(3) at -123 degrees C, as only one conformer was observed with one of the S=O bonds in synperiplanar position to the N(3) group (phi(OS-NN) = -14.8(3) degrees) with respect to the S-N bond. The same conformation was found for trifluoromethylsulfonyl azide, CF(3)SO(2)N(3) (phi(OS-NN) = -23.74(15) degrees), in the solid state. The preference of such a synperiplanar configuration between S=O and N(3) was rationalized by a predominant anomeric interaction of n(sigma)(N) --> sigma*(S-O), as supported by the experiment and quantum chemical calculations.
authors.affiliation: Bergische Universität Wuppertal, FB C-Anorganische Chemie, Gauss Strasse 20, D-42097 Wuppertal, Germany.
authors.forename: Xiaoqing
authors.initials: X
authors.lastname: Zeng
authors.forename: Michael
authors.initials: M
authors.lastname: Gerken
authors.forename: Helmut
authors.initials: H
authors.lastname: Beckers
authors.forename: Helge
authors.initials: H
authors.lastname: Willner
mesh_terms: D001386:Azides / Q000737:chemistry*; D003198:Computer Simulation; D008968:Molecular Conformation; D011789:Quantum Theory; D013055:Spectrophotometry, Infrared; D013441:Sulfinic Acids / Q000737:chemistry*
chemical_list: D001386:Azides; D013441:Sulfinic Acids; C048899:sulfuryl fluoride