Electron density distribution in heterocyclic systems with two adjacent nitrogen atoms
The dipole moments of 19 pyrazole derivatives are determined. Comparing measured dipole moments with those calculated by vector addition, differences in polarization of the pyrazole ring are considered as functions of the natures and positions of substituents. The inadequacy of a symmetrical structure for pyrazole, with a hydrogen linked to both nitrogens, is demonstrated. Comparison of experimentally determined dipole moments with those calculated by the vector method makes it possible to choose between tautomeric structures of 3,4-dibromopyrazole.
KeywordsHydrogen Nitrogen Organic Chemistry Dipole Moment Nitrogen Atom
Unable to display preview. Download preview PDF.
- 1.B. Mazheika, G. I. Chipen, and S. A. Hiller, KhGS [Chemistry of Heterocyclic Compounds], 776, 1966.Google Scholar
- 2.S. A. Hiller, I. B. Mazheika, and I. I. Grandberg, KhGS [Chemistry of Heterocyclic Compounds], 103, 1965.Google Scholar
- 3.S. A. Hiller, I. B. Mazheika, and I. I. Grandberg, KhGS [Chemistry of Heterocyclic Compounds], 107, 1965.Google Scholar
- 4.H. W. Ehrlich, Acta Cryst.,13, 946, 1960.Google Scholar
- 5.Ch. Ph. Smith, Dielectric Behavior and Structure, New York-London, 253, 1954.Google Scholar
- 6.O. A. Osipov, V. I. Minkin, and Yu. B. Kletenik, Handbook of Dipole Moments [in Russian], Izd. RGU, Rostov-on-Don, 1961.Google Scholar
- 7.L. Hunter and H. T. Hayes, J. Chem. Soc., 1, 1941.Google Scholar
- 8.N. E. White and M. Kilpatric, J. Phys. Chem.,59, 1044, 1955.Google Scholar
- 9.I. I. Grandberg, S. V. Tabak, and A. N. Kost, KhGS [Chemistry of Heterocyclic Compounds], 901, 1965.Google Scholar
- 10.A. D. Garnovskii, V. I. Minkin, I. I. Grandberg, and T. A. Ivanova, collection: Nitrogen Rings [in Russian], KhGS, Riga, 1967.Google Scholar
- 11.I. Mazheika, L. Avota, G. Sokolov, and S. Hiller, ZhOKh,34, 3380, 1964.Google Scholar