Use this URL to cite or link to this record in EThOS:
Title: Cyanide responsive lanthanide complexes and supramolecular lanthanide architectures
Author: Zhang, Xuejian
Awarding Body: University of Oxford
Current Institution: University of Oxford
Date of Award: 2020
Availability of Full Text:
Access from EThOS:
Full text unavailable from EThOS. Restricted access.
Access from Institution:
This thesis describes the development of new lanthanide-based luminescent architectures with potential as chemosensors, exploring how the luminescence properties of lanthanide complexes can be altered as a consequence of changes in key analyte concentrations. Chapter 1 provides some background to the field, relating the fundamental properties of lanthanide complexes to their interactions with their surroundings. It also outlines key objectives for sensing cyanide and fluoride in competitive media. Chapter 2 describes the synthesis and properties of a series of lanthanide complexes which incorporate a phenacyl group attached to the well-known DO3A lanthanide binding domain. These complexes show a very limited response to fluoride ions as a consequence of their weak affinity for the charge-neutral lanthanide complex. By contrast, cyanide ions interact with the phenacyl carbonyl group, modulating emission from the lanthanide as a consequence of cyanohydrin formation. These ideas are pursued further in chapter 3. In this chapter, a series of methods are used to explore whether selectivity can be enhanced by using bimetallic complexes. A variety of ligand structures were explored, but the best results were obtained using systems in which two lanthanide-containing complexes were linked together by click reactions. Of these, both the TbEu and EuYb complexes showed the ability to detect cyanide ratiometrically. The EuYb system is probably destined to remain a curiosity, owing to the weak (and hard to detect) emission from the ytterbium centre. However, the TbEu complex has significant potential - offering cyanide selectivity and two-colour emission. Chapter 4 takes a different approach, describing the synthesis of a lanthanide binding rotaxane in which rotaxane formation generates a lanthanide binding site. Studies on this system reveal lanthanide binding in the assembled hosts, albeit with relatively low affinity for lanthanide ions. Chapter 5 draws conclusions from the whole body of work and suggests some avenues that might be explored in future Chapter 6 contains the experimental detail.
Supervisor: Faulkner, Stephen Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available