ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

The Influence of Steric Effect on ¹H NMR, ¹³C NMR, and IR Spectra of Methylated Derivatives of 4-Nitropyridine N-Oxide

A. Puszko and L. Wasylina

Department of Organic Chemistry, Academy of Economics, PL-53 345 Wroclaw

Abstract: The ¹H  NMR, ¹³C NMR, and IR spectra of 2-methyl-, 3-methyl-, 2,3-dimethyl-, a,5-dimethyl-, a,6-dimethyl-, 3,5-dimethyl-, and 2,3,6-trimethyl-4-nitropyridine N-oxides were interpreted. The influence of electron properties of substituents on changes of chemical shifts was analyzed. It was found that ''ortho-effect'' of the methyl group inhibits paramagnetism of the nitro group. The ratio between a given substituted heterocyclic compound, its parent compound and the identically substituted benzene derivatives has been determined. It was found that the effect of the nitro group on chemical shift and the so-called track donation is modified by electronegativity and the position of the substituent.

Full paper in Portable Document Format: 494a176.pdf

Chemical Papers 49 (4) 176–181 (1995)