Supramolecular Crystal Engineering: Design and Synthesis of Novel Persubstituted Aromatic Host Molecules

Rowan, Stuart John (1994) Supramolecular Crystal Engineering: Design and Synthesis of Novel Persubstituted Aromatic Host Molecules. PhD thesis, University of Glasgow.

Abstract

Chapters 1-4 present an introduction into the field of supramolecular crystals. Chapter 1 gives a general introduction into the area of supramolecular chemistry while Chapter 2 concentrates on the more specific field of clathrate chemistry laying down definitions and nomenclature. Chapter 3 talks about the discovery of new host molecules going from chance to specific designing and engineering of hosts. Chapter 4 describes some potential applications for these supramolecular crystals. The research contained in Chapter 5 details the specific use of symmetry and shape in the design of novel host systems based on persubstituted aromatic cores. Section 5.1 talks about the general methods used to synthesise the thiols and phenols required for the synthesis of these persubstituted aromatics. The first type of aromatic cores examined were those with fused benzene rings, Section 5.2. Both anthracene and triphenylene possess C2 axial symmetry and so their persubstituted derivatives were examined for inclusion potential. Perthiosubstituted anthracene molecules were prepared by an extension of the interesting reaction of saturated fluorocarbons with thiolate anions. Decakis(cyclopentylthio)anthracene was shown to be a versatile host. The structure of its 1,4-dioxane clathrate has been established by single crystal X-ray analysis. Persubstituted (arylthio) and (aryloxy) triphenylenes were prepared for the first time. No inclusion compounds were observed for the persubstitued (arylthio) triphenylenes, however, dodecakis(p-phenylphenoxy)triphenylene was shown to include 1,4-dioxane and a series of glymes. Single crystal X-ray analysis was carried out on dodecakis(p-methylphenoxy)triphenylene and dodecakais(p-methylphenylthio)triphenylene to see how these type of molecules pack in the crystalline state. Section 5.3 introduces a new line of investigation. By binding two pentasubstituted benzenes together by a covalent bond or carbon chain we produced linked Hexa-hosts. An investigation into persubstitued biphenyl (O atom link); benzophenone, benzohydrol and diphenylmethane (1 atom link); 1,2-diphenylethane (2 atom link) and 1,6-diphenylhexa-1,6-dione (6 atom link) showed that, so far, only the 1 atom link cores have shown any propensity to include. Single crystal X-ray analysis has been carried out on the decakis(phenylthio)benzophenone/chloroform/acetic acid clathrate to determine its structure. Decakis(phenylthio)benzophenone has also been shown to include ethane-1,2-dithiol, suggesting that this host molecule could be used as a 'molecular bottle' for this odorous reagent. An investigation into silicon linked molecules is described in Section 5.4. However, when bis(pentachlorophenyl)-1,1,2,2-tetramethyldisilane is reacted with sodium phenylthiolate in DMEU, at 60

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Additional Information: Adviser: David MacNicol
• Keywords: Organic chemistry, Molecular chemistry, Physical chemistry
• Date of Award: 1994
• Depositing User: Enlighten Team
• Unique ID: glathesis:1994-75368
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 19 Nov 2019 20:24
• Last Modified: 19 Nov 2019 20:24
• URI: https://theses.gla.ac.uk/id/eprint/75368