Cyclodextrin receptors have been employed to build supramolecular systems consisting of metal and organic photo/redox-active components. The photo-induced communication between redox-active units assembled in water via non-covalent interactions is established. Receptor ligands consisting of a β-cyclodextrin functionalised with a terpyridine or bipyridine unit, ttp-β-CD and mbpy-β-CD respectively, and their ruthenium(II) metal complexes [(ttp-β-CD)Ru(ttp)][PF<sub>6</sub>]<sub>2</sub>, [(ttpβ-CD)Ru(tpy)][PF<sub>6</sub>]<sub>2</sub>, [(ttp-β-CD)<sub>2</sub>Ru][PF<sub>6</sub>]<sub>2</sub>, and [(mbpy-β-CD)<sub>3</sub>Ru][PF<sub>6</sub>]<sub>2</sub> are synthesised and fully characterised. Addition of redox active guests, such as quinones, to aqueous solutions of [(ttp-β-CD)Ru(ttp)][PF<sub>6</sub>]<sub>2 </sub>or [(mbpy-β-CD)<sub>3</sub>Ru][PF<sub>6</sub>]<sub>2</sub>, leads to a quenching of the <sup>3</sup>MLCT emission which is attributed to intramolecular electron transfer from the ruthenium centre to the non-covalently bound guest in the cyclodextrin cavity. Metallo acceptor guests with a hydrophobic binding unit to assure assembly in the cyclodextrin, such as [(biptpy)Os(tpy)][PF<sub>6</sub>]<sub>2 </sub>are investigated to study metal-metal communication. Time resolved spectroscopy and steady state experimental results are given. Binding studies with permethylated β-cyclodextrin to obtain association constants of anthraquinone-4-sulfonic acid, anthraquinone-4-caxboxylic acid and benroquine are performed by emission<i> </i>spectroscopy. Inclusion of a biphenyl unit in permethylated β-cyclodextrin is studied by UV/Vis spectroscopy, using 4’-(<i>p</i>-biphenyl)-2,2’:6’2”-terpyridine and Zn(biptpy)][PF<sub>6</sub>]<sub>2 </sub>as model compounds for a 1:1 and 1:2 inclusion complex formation respectively. The assembly of cyclodextrin recognition sites in macromolecular structures by using simple coordination chemistry is presented. Tris-cyclodextrin complexes are prepared by reaction of the bidentate ligand mbpy-β-CD with iron(II) and rutheniuim(II) or by reaction of the tertendare ligand ttp-β-CD with europium(III). Bis-cyclodextrin complexes axe obtained by addition of iron(II) to ttp-β-CD. The characterisation of the compounds and their luminescent properties are reported.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:651939 |
| Date | January 2001 |
| Creators | Haider, Johanna M. |
| Publisher | University of Edinburgh |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/1842/14954 |
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