Quantum chemical calculation of conformations and rotation barriers of functional groups in arylsulfonyl halides

Citation
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
Citations number
19
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
JOURNAL OF STRUCTURAL CHEMISTRY
ISSN journal
00224766 → ACNP
Volume
41
Issue
5
Year of publication
2000
Pages
749 - 756
Database
ISI
SICI code
0022-4766(200009/10)41:5<749:QCCOCA>2.0.ZU;2-K
Abstract
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.