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Trivalent and tetravalent metal complexes for radiodiagnostics
Hacaperková, Eliška ; Kubíček, Vojtěch (advisor) ; Drahoš, Bohuslav (referee) ; Polášek, Miloslav (referee)
Fluorine-18 is the most utilized nucleus for positron emission tomography (PET). In 2009, incorporation of fluorine-18 to the coordination sphere of Al(III) was introduced as a new alternative for commonly employed compounds with F-C bond. Such a radiotracer consists of two parts: a metal complex with a fluoride and a peptide or a small/part of biomolecule. Shortly after that, first clinical studies showed a promising potential of such com- pounds for clinical use. Despite a great number of papers dealing with this issue, the research is mostly application-driven and focused on the peptide part of the molecule responsible for specific accumulation within the organism. Studies oriented on a sta- bility of metal-ligand-fluorine ternary system are rather rare and only very little is known about such a three-component system from a chemical point of view in gen- eral. However, stability of F-Al bond strongly dependents on the chemical structure of other ligands in the coordination sphere. Pendant arms of a hexadentate ligand (usually used for Al(III) complexation, e.g., H3NOTA) can compete with fluoride and cause its release which leads to unspecific radioactivity accumulation. Lower ligand denticity should increase the F-Al bond stability, but can decrease the stability of the whole complex at the...
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Ligand systems for zirconium complexation
Hacaperková, Eliška ; Kubíček, Vojtěch (advisor) ; Vojtíšek, Pavel (referee)
The aim of this thesis is to synthesize new kind of macrocyclic ligands for complexation of Zr4+ . Zirconium(IV) complexes have potential as contrast agents in immuno-PET. Three macrocyclic ligands L1, L2 and L3 with dif- ferent pendant arms (HOPO, maltol, hydroxamate) were designed. Despite numerous attempts syntheses of L1 and L2 were unsuccessful. Ligand L3 was synthesized and the protonation constants were determined by poten- tiometric titration. Complexes [Zr4+ (L3)] were studied too. Catechol ligand L4 was prepared and complexes with cations Zn2+ , Ga3+ and Zr4+ were investigated. 1
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Zirconium complexes with polyaminocarboxylate ligands
Hacaperková, Eliška ; Kubíček, Vojtěch (advisor) ; Mosinger, Jiří (referee)
This thesis is focused of zirkonium complex with polyaminocarboxylate li- gands. Formation kinetics of zirkonium complex with DTTAPPh ligand was stu- died by spectrophotometry and potentiometry with ISE electrode. According to both methods [Zr(DTTAPPh)] complex is formed rapidly (t99 % < 5 s). In the second part formation kinetics and stability of [Zr(DFO)] complex with fluo- ride anions were studied by potentiometry. For pH range 1-7 average number of fluoride anions coordinated to [Zr(DFO)] complex was determined. This de- pendence shows maxima at pH 3. Number of coordinated fluoride anions as function of increasing fluoride cincentration was studied at pH 3 and 5. Sta- bility of [Zr(DFO)(F)n] complex at fysiological pH was evaluated to determine usability of the complex in vivo.
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