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).
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.
Zeng
Xiaoqing
X
Bergische Universität Wuppertal, FB C-Anorganische Chemie, Gauss Strasse 20, D-42097 Wuppertal, Germany.
Gerken
Michael
M
Beckers
Helmut
H
Willner
Helge
H
D001386:Azides / Q000737:chemistry*; D003198:Computer Simulation; D008968:Molecular Conformation; D011789:Quantum Theory; D013055:Spectrophotometry, Infrared; D013441:Sulfinic Acids / Q000737:chemistry*
D001386:Azides; D013441:Sulfinic Acids; C048899:sulfuryl fluoride