Use this URL to cite or link to this record in EThOS: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.460451
Title: Studies concerning the nitration of coronene
Author: Akhtar, Muhammad Ishaq
ISNI:       0000 0001 3587 2296
Awarding Body: University of Surrey
Current Institution: University of Surrey
Date of Award: 1971
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Abstract:
A complete reinvestigation of the nitration of coronene has been carried out, it having been found that the literature methods and descriptions were unreliable; the preparations of nitrocoronene, dinitrocoronene, trinitro-coronene, and hexanitrocoronene have been carefully studied and precise conditions of their preparations are reported. Nitrocoronene and dinitrocoronene were converted to tri-nitrocoronene and hexanitrocoronene by use of 85% nitric acid and fuming nitric acid respectively. Similarly, tri-nitrocoronene was transformed into hexanitrocoronene by treatment with fuming nitric acid. The infrared spectra of the various nitro derivatives and of the coronene-hexanitro-coronene complex have been discussed. Treatment of nitrocoronene, dinitrocoronene, and trinitrocoronene with phenylhydrazine provided the corresponding amines, which on acetylation with acetic anhydride in pyridine, at room temperature, gave the corresponding N-acetyl derivatives. On prolonged heating under reflux with an excess of acetic anhydride, NN-diacetyl derivatives of the amines were obtained. Oxidation of coronene with sodium dichromate in acetic acid at 118° gave corono-1,2-quinone. Nitrocoronene, on oxidation under similar reaction conditions, furnished nitrocorono-1,2-quinone, which being an ortho-quinone formed the corresponding quinoxaline derivative with o-phenylene-diamine. Corono-1,2-quinone on nitration with 75% nitric acid yielded a dinitrocorono-1,2-quinone, whilst with 85% nitric acid a trinitrocorono-1,2-quinone was formed. In an attempt to determine the orientation of the substituents of bis-(diacetylamino)coronene and hence diaminocoronene and dinitrocoronene, a study of dipole moments was made. The dipole moments of NN-diacetyl derivatives of aminocoronene and diaminocoronene were determined. For the evaluation of the orientation of the substituents within these compounds, the angle of the group moment of the NN-diacetylamino group with its axis of rotation has been calculated from the observed dipole moments of NN-diacetyl-aniline and NNN'N'-tetra-acetyl-p-phenylenediamine, and also from the observed dipole moments of NN-diacetyl-2-naphthylamine, and 2,7-bis-(diacetylamino)naphthalene. From a consideration of the dipole moment data, infrared and n. m. r. spectra, it has been suggested that the most likely structure for the dinitrocoronene mentioned above, is that of 1,5-dinitrocoronene. For trinitrocoronene although 1,4,5-, 1,4,8-, 1,5,9- and 2,3,7-trisubstitutions are probable, the most likely formula is felt to be the 2,3,7 -trinitrocoronene. For hexanitrocoronene a structure having one nitro group on each outer ring is indicated, likely structures are 1,3,6,7,9,12- and 1,3,5,7,9,12-hexanitrocoronene.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.460451  DOI: Not available
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