الفهرس 
Chapter 1: General introductionOnly 14 pages are availabe for public view
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Abstract
Introduction: Magnetic resonance imaging (MRI) is one of the most common clinical imaging procedures which is suited ideally for anatomical imaging of soft tissues. Contrast agents have been used in clinical applications as they have the ability to alter the contrast between different regions in the image. Contrast agents containing transition metal ions which are biologically relevant, have been used as alternatives to Ln(III) contrast agents. In this thesis, three distinct types of transition metal ion based contrast agents including paraCEST, lipoCEST and relaxivity agents will be presented. Results: Paramagnetic transition metal ions, such as high spin (HS) Co(II) bound to TACN macrocycles appended with either alcohol pendants or amide pendants, and HS Ni(II) in TACN, CYCLEN or CYCLAM macrocycles appended with either alcohols or amides, were synthesized and characterized with the goal of developing paraCEST MRI imaging agents, as introduced in Chapters 2 and 3. The two chapters also introduce the first examples of Co(II) and Ni(II) macrocyclic complexes with inner-sphere water as effective water proton shift reagents (SRs). Co(II) complexes with amide pendants produced a strong CEST effect from their exchangeable NH protons, but only at high concentration of the agent, which makes it more challenging to test in animal imaging. Co(II) complexes with hydroxyl pendants produce a very weak CEST effect, due to rapid exchange of the OH proton with bulk water protons. However, complexes with alcohol pendants are excellent water proton SRs, when compared to complexes with amide pendants. Analogous complexes of Ni(II) do not as significantly shift the 1H NMR water resonances. Supramolecular CEST agents, especially those with intra-liposomal water molecules, were studied for the purpose of increasing the sensitivity of CEST agents. Three paramagnetic HS Co(II) macrocyclic complexes CYCLAM were synthesized to prepare the first transition metal liposomal chemical exchange saturation transfer (lipoCEST) agents, to the best of our knowledge, as introduced in chapter 4.Chapter 5 introduces solution chemistry and DFT calculations of three different paramagnetic HS Fe(III) macrocyclic complexes containing 2-hydroxypropyl pendant groups on TACN macrocycle. The chapter also introduces the first examples of transition metal containing liposomes that produce CEST or function as T1 or T2 agents (relaxivity agents.