Vv. Kislov et al., Quantum chemical calculation of conformations and rotation barriers of functional groups in arylsulfonyl halides, J STRUCT CH, 41(5), 2000, pp. 749-756
The semiempirical PM3 method is used to calculate the potential functions o
f internal rotation of the functional groups -SO2Cl -NO2, -CH3, -OCH3, and
-NH2 of benzenesulfonyl halide molecules (PhSO(2)Hal, Hal = F, Cl, Br, I) a
nd twelve substituted derivatives of benzenesulfonyl chloride. Molecular co
nformations have been determined and internal rotation barriers of the func
tional groups have been calculated. For meta- and para-substituted benzenes
ulfonyl chlorides, the projection of the S-Hal bond is perpendicular to the
plane of the benzene ring. The rotation barriers of the -SO(2)Hal group of
benzenesulfonyl halides increase in the series Hal = F, Cl, Br, I. The rot
ation barriers of the -SO2Cl group of benzenesulfonyl chloride with meta- a
nd para-substituents slightly increase with the electron-donor properties o
f the substituent. The rotation barriers of the functional groups of ortho-
substituted benzenesulfonyl chlorides are 3 or 4 times as high as those of
the meta- and para-isomers. For pam-substituted benzenesulfonyl chlorides,
the rotation barriers of the functional groups increase in the order -CH3,
-NO2, SO2Cl, -OCH3, -NH2.