Investigating the impact of ligand modification on luminescent lanthanide complexes

Thesis

This thesis describes

Chapter 1 introduces the field of lanthanide chemistry, from electronic structure to the influence of coordinating ligands, with a particular focus on the luminescent properties. It describes the various methods in which ligand choice and modification has allowed for the development of responsive luminescent lanthanide probes.

Chapter 2 describes the synthesis, and optical properties of kinetically stable, photoswitchable, emissive lanthanide complexes, which are controlled by four orthogonal wavelengths of light. The complete orthogonality achieved between the photoswitching and the excitation and emission of the lanthanide has allowed for applications in optical information storage to be realised.

Chapter 3 details the preparation of a family of related binuclear lanthanide probes for the detection of redox environments via magnetic resonance or optical imaging. Common classes of compounds including nitrophenyl, azide and azobenzenes were incorporated into binuclear lanthanide complexes, which upon complete reduction, yielded a shared product, the corresponding aniline. This reduction for Gd(III) complexes resulted in a change in realxivity, and for Tb(III) complexes, an impressive turn on of long lived bright green emission.

Chapter 4 investigates the structure and speciation of common heptadentate lanthanide complexes in solution. The isomeric distribution of twisted square antiprismatic and square antiprismatic geometries were determined independently by detailed and robust analysis of the luminescence spectra, and by 1H NMR spectroscopy. This novel methodology highlights the structural information available from lanthanide luminescence.

Chapter 5 explores the structure and speciation in solution of binuclear lanthanide complexes introduced in Chapter 3, in detail. Particularly focussing on the speciation as a function of pH. This allowed insight into the structure in solution of complex and exciting binuclear complexes.

Chapter 6 summarises the conclusions of this thesis.

Chapter 7 describes the experimental procedures used in this work, including the synthesis and characterisation of all complexes studied in Chapters 2-5.

Authors: Simms, CH

• DOI: 10.5287/ora-4jkkbwep2
• Type of award: DPhil
• Level of award: Doctoral
• Awarding institution: University of Oxford
• Language: English
• Keywords: luminescence; inorganic chemistry; spectroscopy; lanthanides
• Subjects: Rare earth metal compounds; Luminescence spectroscopy; Rare earths; Nuclear magnetic resonance, Pulsed; Bioinorganic chemistry; Chemistry, Inorganic