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Contracted phthalocyanine macrocycles : conjugation with nanoparticles and the first synthesis of meso-substituted boron SubTriBenzoDiAzaPorphyrin hybrids (SubTBDAPs)

The first part of this thesis is concerned with the attachment of subphthalocyanines to quantum dots. The macromolecule was chosen as encapsulant due to its perfect curvature and interesting optical properties. CdSe quantum dots are well-known materials with size-dependent properties that makes them unique. Hence, some subphthalocyanines bearing functional groups with affinity for the CdSe surface were synthesised by means of cross-coupling reactions. Small nanoparticle size (2.6 nm) quantum dots have been synthesised, capped with a layer of oleic acid molecules that confers them stability, and characterised by means of UV-Vis, emission and NMR spectroscopies. The original ligands were replaced by ligand exchange processes monitored by 1HNMR spectroscopy. The experiments consist of titrations of CdSe-OA solutions with known concentrations of the new ligand. In this work, titrations using 3-ethynylpyridine, benzyl alcohol and phenylacetic acid have been performed. Parallel results in our group, involving the herein synthesised subphthalocyanine bearing pyridyl – groups, towards the attachment to the nanoparticle’s surface are also described. Subphthalocyanine bearing three carboxylic acids is demonstrated to be the most promising candidate for this project. However, attempts to synthesise such a molecule by direct approach strategies were unsuccessful. Experiments with sodium periodate-subphthalocyanine conjugates gave promising and encouraging results, opening the possibility of accessing subphthalocyanines with carboxylic acid groups by means of deprotecting silyl groups. The second part of this thesis is based on the results obtained towards the first syntheses of hybrid structures whose structure lies between subphthalocyanines and subporphyrins, SubTriBenzoDiAzaPorphyrins (SubTBDAPs). The key intermediates are aminoisoindolene precursors that provide the methine bridge, and substitution with the meso-phenyl ring. Boron trichloride has been used in a two-step, one-pot reaction in a preliminary strategy to give access to the hybrids. However, trialkoxyborates are the preferred boron source; they provide the apical substituent, as well as act as Lewis acid and template. The latter synthesis is versatile and gives modest yields and highly pure materials, but most importantly allows control over the apical and the meso-substituents in one single step. The new hybrids exhibit interesting optical and rotational characteristics that have been fully investigated by means of UV-Vis, emission, NMR spectroscopies, variable temperature experiments and mass spectrometry. In this work the first crystal structures elucidated for a wide range of new hybrids are also presented.

Identiferoai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:665968
Date January 2015
CreatorsRemiro Buenamanana, Sonia
PublisherUniversity of East Anglia
Source SetsEthos UK
Detected LanguageEnglish
TypeElectronic Thesis or Dissertation
Sourcehttps://ueaeprints.uea.ac.uk/54344/

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