Design of lanthanide-based metal complexes for probing hypoxia and redox

Thesis

The modulation of redox balance is imperative to maintain cell and organ functions. As a result, tissue hypoxia and redox have intimate correlation with various diseases. Over the past decade, the development of responsive probes that are capable of monitoring the biological activities and biomarkers has attracted great attention. This thesis mainly focuses on designing redox and hypoxia-responsive lanthanide complexes combining the paramagnetizm and luminescence.

In Chapter 2, by incorporation of redox-sensitive nitroaromatic groups, the reductive environment evokes a cleavage of the chromophore in order to cause changes in the luminescence of lanthanide trivalent ions, chemical shifts of protons and relaxivity of metal complexes. The multiple applications of stable and versatile lanthanide complexes are discussed in the field of optical imaging and magnetic resonance (MR) imaging.

In Chapter 3, based on the study presented in Chapter 2, naphthyl analogues with longer excitation wavelengths were investigated. The impact of minimal structural modifications to the antenna on the luminescence properties of lanthanide was examined through the demethylation of methoxy groups. Additionally, the pH sensitivity of lanthanide complexes incorporating naphthol and phenol was compared.

In Chapter 4, 1,8-naphthalimide was incorporated into lanthanide complexes. By modifying electron-rich or electron-deficient moieties at the C-4 position, its ability to sensitize lanthanide ions and bind to proteins was investigated.

In Chapter 5, building on the findings from Chapter 4, a boronate group was introduced to 1,8-naphthalimide, enabling the design of a peroxide-responsive fluorescent switch through the formation of a push-pull system.

Authors: Wang, X

• DOI: 10.5287/ora-qqgbewq7a
• Type of award: DPhil
• Level of award: Doctoral
• Awarding institution: University of Oxford
• Language: English
• Keywords: MRI contrast agents; redox probe; lanthanide chemistry
• Subjects: Rare earth metals