Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.639908
Title: Hydrogen bonding and covalent coupling in adsorbed molecular monolayers
Author: Garfitt, Jason Michael
ISNI:       0000 0004 5366 0264
Awarding Body: University of Nottingham
Current Institution: University of Nottingham
Date of Award: 2014
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Abstract:
This thesis examines multiple different molecular networks adsorbed on several different substrates, namely, highly oriented pyrolytic graphite (HOPG), Au(111) and graphene. STM investigations into hydrogen-bonded structures formed by closely related tetracarboxylic acid molecules were performed. The molecule pterphenyl-3,5,3,5-tetracarboxylic acid (TPTC), which is known to form random tiling networks, was observed on a graphene on copper substrate. The network formed from deposition of TPTC from nonanoic acid was examined statistically. Aqueous solutions of TPTC were also examined on HOPG where a new structure, distinct from the random tiling, was observed. Aqueous solutions of related molecules biphenyl-3,3',5,5'-tetracarboxylic acid (BPTC) and quaterphenyl-3,3',5,5'-tetracarboxylic acid (QPTC), were also studied on HOPG. QPTC formed a similar structure to the aqueous solutions of TPTC, but BPTC formed two different phases, one of which was a kagome network. Addition of nonanoic acid to a dried network of TPTC deposited from aqueous solution resulted in solvent induced recrystallisation into a random tiling network comparable to that observed on graphene on copper, which was statistically analysed. Studies investigating the potential for covalent bonded molecular networks identified two distinct phases of the molecule 1,3,5-Tri(4-bromophenyl-benzene (TBPB)) adsorbed on Au(111). Concentration variation indicates an island based growth mechanism for these domains from solution. Dimerisation of TBPB was achieved by deposition onto heated substrates and a discussion of possible reasons for the reaction termination at dimers is provided. Attempts to repeat the TBPB experiments on graphene on copper failed due to excessive corrosion. Variations using larger molecules failed due to lack of solubility. Preliminary experiments on 10,10'-dibromo-9,9'-bianthryl (DBrBA) showed promise but were irreproducible, however micron scale dendritic structures were observed suggesting poor compatibility with the solvent. Finally, a discussion of the development of a nickel catalysis based graphene fabrication method is given and the limits of what is achievable with this method are discussed. The results from this thesis highlight the importance of solvent selection for the future understanding of molecular network fabrication. We also demonstrated the feasibility of covalently bonded networks prepared in ambient conditions.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.639908  DOI: Not available
Keywords: QC770 Nuclear and particle physics. Atomic energy. Radioactivity ; QD450 Physical and theoretical chemistry
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