The equilibrium between the iso and the normal forms of 9-nitrofluorene
- 22 Downloads
A series of bromometric titrations of solution of iso-9-nitrofluorene in ethanol, dioxane and benzene was run.
The iso-form is thermodynamically more stable in the crystalline form than is the normal form; equilibria are established in solution in which the content of the normal form is greater with lower polarity of the solvent. The normal form of 9-nitrofluorene cannot be isolated since it disproportionates forming 1,2-dinitro1,2-dibiphenylene-ethane and fluorenone oxime. This reaction occurs at a lower rate than the reaction of formation of the normal form from the iso-form. Consequently, temporarily large concentrations of the normal form exist in solution and these were established by a chemical route.
The greater stability of the iso-form of 9-nitrofluorene is determined by the tendency of the cyclopentadiene ring to form an aromatic sextet by attracting electron pairs from the nitro group.
KeywordsBenzene Titration Normal Form Dioxane Oxime
Unable to display preview. Download preview PDF.
- F. R. Gross and C. K. Ingold, J. Chem. Soc. 1928, 1268.Google Scholar
- G. W. Wheland and D. E. Mann, J. Chem. Phys. 17, 264 (1949); E. D. Bergmann and E. Fischer, Bull. Soc. chim. France, 1684 (1950).Google Scholar
- D. Lloyd and J. S. Snezum, Chemistry and Industry, 1221 (1955).Google Scholar
- F. Ramirez and S. Levy, J. Organ. Chem. 21, 488 (1956).Google Scholar
- W. v. E. Doering and C. H. DePuy, J. Amer. Chem. Soc. 75, 5955 (1953).Google Scholar
- C. F. H. Allen and J. A. Van Allan, J. Amer. Chem. Soc. 72, 5165 (1950).Google Scholar
- C. K. Ingold and J. A. Jessop, J. Chem. Soc. 1930, 713.Google Scholar
- L. Horner and E. Lingnau, Liebigs Ann. Chem. 591, 23 (1955).Google Scholar
- C. D. Nenitzescu and D. A. Isacescu, Ber. Dtsch. Chem. Ges. 63, 2484 (1930).Google Scholar
- W. Wislicenus and M. Waldmüller, Ber. Dtsch. Chem. Ges. 41, 3334 (1908).Google Scholar
- C. K. Ingold, Structure and Mechanism in Organic Chemistry, Cornell University Press, N. Y. 1953, p. 535.Google Scholar
- D. Turnbull and S. H. Maron, J. Amer. Chem. Soc. 65, 212 (1943).Google Scholar
- J. Thiele, Ber. Dtsch. Chem. Ges. 33, 670 (1900).Google Scholar
- W. Wislicenus and K. Pfeilsticker, Liebigs Ann. Chem. 436, 36 (1924).Google Scholar
- K. H. Meyer and P. Kappelmeyer, Der. Dtsch. Chem. Ges. 44, 278 (1911); K. H. Meyer, ibid, 45, 2843 (1912).Google Scholar
- K. H. Meyer and P. Wertheimer, Ber. Dtsch. Chem. Soc. 47, 2374 (1914).Google Scholar