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2 Polish Journal of Chemistry

2 2003

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Predominance of Amino-Sulfonyl Hydrogen Bonding in (Z)-2-Benzene-sulfonyl-1-phenyl-2-(phenylhydrazono)ethanones in Crystals adn in Solution: An Experimental NMR and X-ray Crystallographic and Theoretical Ab initio and DFT/GIAO Studies

Kolehmainen E., Zakrzewski A., Zakrzewska A., Nissinen M., Ośmiałowski B., Gawinecki R.

Polish Journal of Chemistry

2003

Vol. 77 / nr 1

31-45

1H, 13C, and 15N NMR spectra show that (Z)-2-benzenesulfonyl-1-phenyl-2-(phenylhydrazono) ethanone is the only tautomeric form detected in chloroform solution. Substituent in the phenylhydrazone moiety does not affect this tautomeric preference. Ab initio calculations show that (Z)-2-benzenesulfonyl-1-phenyl-2-(phenylhydrazono)ethanone is really favoured over its proton transfer products in chloroform solution. This shows that N-H...OS(O) interaction is much stronger than the hydrogen bonds in other tautomeric forms. The (Z)-2-benzene-sulfonyl-1-phenyl-2-(phenylhydrazono)ethanone tautomer was also detected in the crystal state.

1H, 13C and 15N NMR Spectral and X-ray Structural Studies of 2-Arylsulfonylamino-5-chlorobenzophenones

Kolehmainen E., Nissinen M., Janota H., Gawinecki R., Ośmiałowski B.

Polish Journal of Chemistry

2003

Vol. 77 / nr 7

889-894

Six 2-(4-R-phenylsulfonylamino)-5-chlorobenzophenones were prepared and their 1H, 13Cand 15NNMRspectra recorded and assigned. The dependence between the chemical shift of the amide proton and Hammett _ substituent constants is of the V type. Substituent effect on the chemical shift of the amide nitrogen atom was found insignificant. X-ray analysis shows that the terminal benzene rings in 2-(4-nitrophenylsulfonylamino)-5-chlorobenzophenone are located close to each other. They are not, however, parallel, dihedral angle between them being equal to 10.86 deg (MP2/6-31G**//HF/6-31G** ab initio calculations show this to be 20.44 deg). This shows that the mutual orientation of two benzene rings in the molecule of this compound is caused by the _-_ stacking. It is additionally reinforced by the intramolecular NH…O=C hydrogen bond. Except the dihedral angle between the benzene rings, X-ray determined structure of 2-(4-nitrophenylsulfonylamino)-5-chlorobenzophenone is very similar to this optimized by the ab initio calculations.