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oai:bura.brunel.ac.uk:2438/78802014-11-01T11:34:55Zcom_2438_58com_2438_23col_2438_4327col_2438_3672

Waters, DN Yeadon, Alan 2014-01-14T14:19:29Z 2014-01-14T14:19:29Z 1985 http://bura.brunel.ac.uk/handle/2438/7880 This thesis was submitted for the degree of Doctor of Philosophy and was awarded by Brunel University. The full crystal structures of three polymorphs of 4-methyl-2-nitroacetanilide (MNA) are described. The white form (MNA-l), is the most stable form. The least stable form is the amber farm (MNA-2). The yellow form (MNA-3) has been found to change in a topotactic manner into the white form. The relationships between the three polymorphs are discussed and possible mechanisms to account for the topotactic phase changes are presented. The polymorphs show different i.r. and Raman spectra in the solid state. These spectra, and those of deuterated analogues are interpreted and their differences explained. A study of the proton and 13-C n.m.r. spectra show that the conformation of flexible MNA molecules is markedly dependent on the nature of the solvent. The ability of other o-nitroacetanilides to exist in a white (intermolecular) and yellow (intramolecular hydrogen bonded) forms has been examined. Finally, details of the synthesis of these compounds and an account of the examination of MNA polymorphs by differential scanning calorimetry (d.s.c) are described. A description of computer programs used, including one in BASIC which will enable the contents of unit cell(s) to be viewed, is given. Submitted by Terese Jonsson (terese.jonsson@brunel.ac.uk) on 2014-01-14T14:19:13Z No. of bitstreams: 1 353748.pdf: 22838603 bytes, checksum: 6adf59451fc1b9b9a89443093970cfba (MD5) Approved for entry into archive by Terese Jonsson(terese.jonsson@brunel.ac.uk) on 2014-01-14T14:19:29Z (GMT) No. of bitstreams: 1 353748.pdf: 22838603 bytes, checksum: 6adf59451fc1b9b9a89443093970cfba (MD5) Made available in DSpace on 2014-01-14T14:19:29Z (GMT). No. of bitstreams: 1 353748.pdf: 22838603 bytes, checksum: 6adf59451fc1b9b9a89443093970cfba (MD5) Berkshire Education Committee en http://bura.brunel.ac.uk/bitstream/2438/7880/1/FulltextThesis.pdf Polymorphism 4-methyl-2-nitroacetanilide Topotactic phase change MNA polymorphs A study of the polymorphism of 4-methyl-2-nitroacetanilide and related compounds Thesis