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Structure analysis of molecular crystals
Janíček, Jakub ; Císařová, Ivana (advisor) ; Vojtíšek, Pavel (referee)
Summary: Diploma thesis covers characterization of molecular crystals by X-ray structural analysis. N-carbamimidazoylisonikotinamid and 1-phenylguanidin were chosen, because their potential use in second harmony generation. Their salts with inorganic acids were prepared and determined their structures. Phase transition of 4,6-diaminopyrimidinium nitrate was studied by x-ray diffraction and differential scanning calorimetry. This phase transition is accompanied by thermosalient effect, causing that the crystals jump. Keywords: thermosalient, jumping crystal, X-ray diffraction, non-linear optics, N-carbamimidazoylnikotinamid, 1-phenylguanidin, 4,6diaminopyrmidin.
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pH-probes for Magnetic Resonance Imaging
Šrolerová, Tereza ; Kotek, Jan (advisor) ; Vojtíšek, Pavel (referee)
Macrocyclic ligands are known for their ability to bind paramagnetic lanthanide metal ions to form kinetically inert and thermodynamically stable complexes that can be used as contrast agents for MRI. This thesis deals with the study of new ligands derived from the known parent ligand H8DOTP - 1,4,7,10-tetraazacyclododecane with four pendant methylenephosphonate groups. The prepared new derivatives contain two different pairs of pendant groups, always in opposite positions of the macrocycle. One of the pairs are methylenephosphonate groups, the other pair are methylenephosphinate groups with different substituents on the phosphorus atom. Specifically, it is a compound with a P-H phosphinate group (H6DO2P2PH ), a phenyl group (H6DO2P2PPh ) and a trifluoroethyl group (H6DO2P2Ptfe ). The thesis describes the synthesis of the target ligands, the preparation of their complexes with paramagnetic ions Eu3+ and Yb3+ and their further study using NMR spectroscopy (pH NMR titration and relaxometric NMR measurements). Keywords: H4DOTA, H8DOTP, MRI, contrast agent, lanthanides, macrocyclic ligands, paramagnetic complexes
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Contrast agents for 19F magnetic resonance imaging
Dobrovolná, Tereza ; Kotek, Jan (advisor) ; Vojtíšek, Pavel (referee)
Complexes of transition metal ions with ligands containing fluorine atoms represent an interesting group of 19 F MRI contrast agents that could facilitate the diagnosis of various diseases. The presence of a paramagnetic metal ion in the vicinity of the 19 F nucleus results in shorter relaxation times and the possibility to obtain more NMR spectra in a given time, leading to better resolution. This work deals with the synthesis of the fluorinated macrocyclic ligand H3NOTPtfe , the preparation of its complexes with transition metal ions, their characterization and study by methods suitable for assessing their applicability in 19 F MRI, i.e. relaxometric NMR measurements and electrochemistry. The results show that the chosen concept is promising for 19 F MRI. The prepared complexes are applicable as 19 F MRI contrast agents, some even as redox active 19 F MRI "smart" contrast agents. The best properties were observed for the complex [Co(NOTPtfe )]− . Keywords: heteronuclear MRI, contrast agent, fluorine, PRE effect, spin relaxation, magnetic resonance imaging, paramagnetic complexes
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Utilization of modified polyethylenes as macroscopic ligands
Ráliš, Václav ; Pinkas, Jiří (advisor) ; Vojtíšek, Pavel (referee)
Charles University in Prague Faculty of Science Department of Inorganic Chemistry Author: Václav Ráliš Supervisor: Mgr. Jiří Pinkas, Ph.D.prof. Consultant: RNDr. Petr Štěpnička, Ph.D., DrSc. Title: Utilization of modified polyethylenes as macroscopic ligands Termination of growing polyethylene (PE) chain by silane HSiR1 R2 R3 leads to polymers bearing chain-end silyl group (SiPE). These materials can be further modified to form polymers terminated by silanol group (PE-SiOH). Using suitable default conditions, a modified PE with relatively low molecular weight (Mn ~1000 Da) and useful solubility profile can be obtained. Due to the presence of reactive silanol or hydrosilane groups, such materials can serve as a support for grafting a wide range of metals. The aim of the thesis is to verify the possibility of grafting metals by chemical bonding on a modified PE (which in this particular case can be seen as a "slightly larger" ligand. Prepared materials will be tested with regard on their possible use in catalysis. This research is interdisciplinary at the border between inorganic (coordination chemistry) and physical chemistry (polymers, catalysis). Keywords: supported complexes, modified polyethylene, catalysis
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Coordinatively unsaturated complexes of macrocyclic amides
Mojžíšová, Adéla ; Kotek, Jan (advisor) ; Vojtíšek, Pavel (referee)
Growing number of citizens in developed countries suffers from neurodegenerative diseases. According to World Health Organization (WHO) dementias affect 55,2 million people and their incidence was doubled over last 20 years. Althought the number of cases is increasing, there is still no effective way for their diagnostics or treatment. With development of implantology, there are still common bacterial diseases as a result of formation of bacterial biofilms on unnatural surfaces. The development of synthetic nucleases which could prevent formation of biofilms is therefore one of the scientific aims. The aim of this bachelor thesis is preparation of polyazamacrocycles which contain amino and amidic functional groups. It can be assumed that these compounds will deprotonate amidic groups after coordination of copper(II) ion. These systems are designed to serve as agents for diagnostics of neurodegenerative diseases using positron emission tomography. In addition, as the complexes are coordinatively unsaturated, they can potentially show an artificial nucleases activity and ability to hydrolytically cleave bacterial biofilms.
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Dimer macrocyclic complexes
Rys, Jan ; Kubíček, Vojtěch (advisor) ; Vojtíšek, Pavel (referee)
This thesis is focused on dimer macrocyclic ligands and their complexes. Two dimer macrocyclic ligands based on ligand DO3A, linked with xylyl linker were prepared (BDO3A-p-X a BDO3A-m-X). Both synthetized ligands were characterized using NMR, MS, EA and in the case of BDO3A-p-X by X-ray crystallography. Data for calculating pseudo-first order reaction rates for complexations with Ce3+ metal ion and their pH dependency were obtained by use of UV/VIS spectrophotometry. Obtained data were compared to structurally close monomer ligand BnDO3A. Dimer ligands display different coordination properties based on proximity and position of coordinating cavities. Both prepared ligands behave differently than structurally close monomer ligand BnDO3A.
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Bifunctional chelators for selective copper(II) binding
Paúrová, Monika ; Kotek, Jan (advisor) ; Vojtíšek, Pavel (referee)
Title: Bifunctional chelators for selective copper(II) binding Autor: Bc. Monika Paúrová Department: Department of Inorganic Chemistry, Faculty of Science Supervisor: doc. RNDr. Jan Kotek, Ph.D. Supervisor's e-mail: modrej@natur.cuni.cz Abstract: In this Master thesis, cyclam bifunctional derivatives bearing pendant phosphinate groups (4-methyl-11-p-aminobenzyl-1,4,8,11-tetraazacyclotetradecane-1,8- bis(methylenephosphinic acid)) and phosphonate groups (4-methyl-11-p-aminobenzyl- 1,4,8,11-tetraazacyclotetradecane-1,8-bis(methylenephosphonic acid)), were prepared and studied as potential ligands for complexation of divalent copper. These ligands are suitable for binding to a macromolecular carrier. Keywords: radiomedicine, copper, cyclam, chelating agent, phosphinate, phosphonate, kinetic inertness, kinetic lability, thermodynamic stability
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Study of thermodynamic stability of complexes with polydentate ligands
Böhmová, Zuzana ; Kubíček, Vojtěch (advisor) ; Vojtíšek, Pavel (referee)
Acid-base and coordination properties of macrocyclic ligand 1-oxa-4,7- diazacyclononane-4,7-bis(methylenephosphonic acid) were investigated. Protonation constants and stability constants with Ca2+ , Mg2+ , Cu2+ , Zn2+ , Mn2+ a Ga3+ metal ions were determined by potentiometry. Keywords Potentiometry, coordination chemistry, azacycles.
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