Use this URL to cite or link to this record in EThOS:
Title: Metal-mediated redox manipulations of CO2 and CO towards 11C for PET imaging
Author: Anders, David Alexander
ISNI:       0000 0004 7657 0413
Awarding Body: Imperial College London
Current Institution: Imperial College London
Date of Award: 2017
Availability of Full Text:
Access from EThOS:
Access from Institution:
This thesis is concerned with the development of the first electrochemical [11C]CO2 to [11C]CO reduction with the ultimate aim of generating a device that could not only carry out the initial conversion but also trap the subsequent product ([11C]CO) and release it in a controlled manner so that [11C]CO may become more widely adapted within the PET radiochemistry field. The opening chapter focusses on the use of PET for biomedical imaging with a particular focus on the cyclotron generated isotopes 18F, 13N, 15O and 11C and the current tracers in clinical use. The chapter will then address the shortage of tracers in the clinic made from [11C]CO2 and [11C]CO later discussing current research into utilising both of these gases and the challenges that arise for using [11C]CO as a precursor. Chapter 2 begins by introducing electrochemical CO2 reduction and the current state of the art as far as both homogeneous and heterogeneous CO2 reduction are concerned. Building on the work already done on Ni(cyclam), the results section will begin exploring Ni(cyclam)'s ability to poison itself with CO and release it over time with a gas chromatography study. This will be followed by discussion about the benefits and disadvantages of using a Zn(cyclen) catalyst which was used for the first time as a CO2 reduction catalyst. Chapter 3 shows a solid support gold coated nanoparticle being used for CO2 reduction. The catalysts trialled in Chapter 2 and 3 are then used in the radiochemistry lab in chapter 4 to convert [11C]CO2 to [11C]CO in aqueous conditions and converted the [11C]CO to [11C]N-benzylbenzamide using a two vial set-up. This demonstrated the first electrochemical conversion in a PET chemistry setting. Trapping of [11C]CO2 within the electrochemical cell was improved by adding base before adding acid to release it. Improvements were sort by altering the electrode set-up and moving to organic solvents. Chapter 5 describes the synthesis and characterisation of known and novel porphyrin and corrole complexes with local proton sources designed in the ligand to help CO2 reduction in organic solvents. A selection of these were then solid supported onto a carbon black electrode in chapter 6 and trialled as CO2 reduction catalysts and potential ability as a reversible CO store in preparation for further radiochemical experiments.
Supervisor: Long, Nicholas Sponsor: Institute of Chemical Biology ; Medical Research Council
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral