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Synthesis of a ferrocenyl-substituted bicyclic phosphite
Bárta, Ondřej ; Štěpnička, Petr (advisor) ; Kubíček, Vojtěch (referee)
Title: Synthesis of a ferrocenyl-substituted bicyclic phosphite Author: Ondřej Bárta Institution: Faculty of Science, Charles University in Prague, Department of Inorganic Chemistry Supervisor: prof. RNDr. Petr Štěpnička, Ph.D. This thesis describes the synthesis of a novel bicyclic phosphite ester, {N-(2,6,7-trioxa-1-phosphabicyclo[2.2.2]oct-4-yl)carbamoyl}ferrocene (3). This compound was obtained by the reaction of phosphorus trichloride with the appropriate tris(hydroxymethyl)methyl-amide in the presence of triethylamine or pyridine. The reaction conditions were optimized by varying the solvent, reaction temperature and the base to achive the highest possible yield of the product and to enable its easy and effective chromatographic purification. A new compound, 2-ferrocenyl-4,4-bis(chloromethyl)-4,5-dihydro-1,3-oxazol (4), was isolated as the by-product of this reaction. Compound 3 was further used to prepare the carbonyl complex cis-[W(CO)4(3-κP)2] (5). All the newly prepared compounds were characterized by NMR spectroscopy, mass spectrometry, infrared spectroscopy and by elemental analysis, and their molecular structures were determined by X-ray diffraction analysis. Hydrogen bonds are cooperating to form one-dimensional chains in the crystals of phosphite 3 and solvate 4 × ½ H2O or...
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Porphyrine conjugates for MRI
Dušek, Pavel ; Vojtíšek, Pavel (advisor) ; Kotková, Zuzana (referee)
The theoretical part of this bachelor's thesis focuses on clinical applications of MRI methods. It also presents a list of gadolinium-based contrast agents used in clini- cal practice. A new conjugate of 1,4,7,10-tetraazacyclododecane-4,7,10-triacetate-1- {methyl-[(4-aminophenyl)methyl]phosphinic} acid and 5,10,15,20-tetrakis(4-amino- phenyl)porphyrin potentially active as a contrast agent is designed on the basis of this review. Due to unique properties of porphyrin unit, this compound may act as a bimodal contrast agent or contrast agent for functional imaging. The target compound and its ytterbium-complex were synthesized and partially characterized.
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Synthesis and properties of a ferrocenyl-substituted diphosphine
Verníček, Marek ; Štěpnička, Petr (advisor) ; Vojtíšek, Pavel (referee)
Title: Synthesis and properties of a ferrocenyl-substituted diphosphine Author: Marek Verníček Department: Department of Inorganic Chemistry (Faculty of Science, Charles University in Prague) Supervisor: prof. RNDr. Petr Štěpnička, Ph.D. In this work, a new ligand was prepared, namely N,N-bis[2-(difenylfosfino)ethyl]amide of ferrocenecarboxylic acid. This ligand was obtained by the reaction of pentafluorophenylferrocenecarboxylate, which was newly synthesized, with the appropriate amine. The ligand was characterized by 1 H, 13 C, 31 P NMR spectroscopy, elemental analysis, IR spectroscopy and by mass spectrometry. Subsequently, a sulphide was prepared from this diphosphine-amide by the reaction with sulfur in toluene at elevated temperature. The sulphide was characterized in the same manner and also analyzed by single-crystal X-ray diffraction analysis. The coordination properties of the ligand were examined in a reaction with [PtCl2(cod)] (cod = cyclooctadiene) in dichloromethane. The resulting complex was studied by 1 H NMR, mass spectrometry, elemental analysis and by X-ray structural analysis. Keywords: ferrocene; phosphine ligands; amidophosphines; platinum(II) complexes; crystal structure.
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Study of tebuconazole complexes with metal ionts
Norková, Renáta ; Jaklová Dytrtová, Jana (advisor) ; Vyskočil, Vlastimil (referee)
Tebuconazole belongs to widely utilized plant fungicides, mostly in vineyards. Its traces are present in plant tissues, wine as well as in soil. The aim of the study was to determine stoichiometries and stabilities of metal (Cu, Zn, Cd, Ca and Ag) complexes with tebuconazole (1) by means of electrospray ionization mass spectrommetry (ESI-MS). It was found that the complexes of tebuconazole with copper ions are particularly stable ([Cu(1)]+ has appearance energy 224 kJ·mol-1 , corresponding with the dissociation of the water molecule from the tebuconazole molecule), while the stability of another tebuconazole complexes is lower, about 150 kJ·mol-1 . In real environmental samples, the detection of 1 itself is hampered by its spreading into various species. The method involved here is based upon a hyphenation of electrochemistry (amperometry) and electrospray-ionization mass spectrometry (ESI-MS). It uses the fact that Cu creates very stable complexes with 1. We demonstrate that at appropriate potentials (at higher than 500 mV) Cu cations can be generated in an electrochemical cell and subsequently form complexes with 1 present in the sample. The resulting complex [Cu(1)]+ is detected with ESI-MS. The intensity of detected complexes depends on the concentration of 1 and the oxidation level of the...
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Chemical and thermal stability of humic complexes
Nováková, Tereza ; Pospíšilová, Ľubica (referee) ; Klučáková, Martina (advisor)
The aim of this diploma thesis was the study of relation between chemical and thermal stability of complexes of humic acids with heavy metals, namely nickel, cobalt and copper. Complexes were prepared with metal solutions of three different initial concentrations. Through UV-VIS spectrophotometry were determined adsorbed amounts of incorporated metal ions in the structure of humic acid; it was affirmed that amount of bounded metal ions increases with increasing initial concentration. Chemical stability was determined as an amount of released metal ions, two of extraction agents were used (solution of MgCl2 and HCl), total bounded amount was distribute into three different fractions; residual fraction, strongly bound fraction and mobile and ion-exchangeable fraction. Changes that occured in the structure of humic acids after complexation and extraction were investigated by FT-IR spectrometry. Thermo-oxidative stability was tested through thermogravimetric analysis (TGA) and differential scanning calorimetry. The results of this diploma thesis has showed comparision of complexes of two different humic acids. They have confirmed an impact of each metal ion on thermo-oxidative stability of humic acids. The relation between chemical and thermal stability was compared through correlation of data obtained by these methods.
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Stability of complexes of humic acids with heavy metals
Nováčková, Kristýna ; Šmejkalová, Daniela (referee) ; Klučáková, Martina (advisor)
Tato diplomová práce je zaměřena na porovnání termo-oxidační a chemické stability kovových komplexů huminových kyselin. Pro tyto experimenty byly vybrány tři prvky reprezentující skupinu těžkých kovů (kobalt, měď a nikl). Použitá huminová kyselina byla extrahována z Jihomoravského lignitu. Pro přípravu komplexů byly využito různě koncentrovaných roztoků kovů, aby bylo možné pozorovat vliv jejich počáteční koncentrace na obě studované stability připravených komplexů. Chemická stabilita kovových komplexů byla posuzována z hlediska uvolňování kovových iontů ze struktury huminové kyseliny do dvou různých extrakčních činidel (HCl, MgCl2). Termo-oxidační chování bylo zkoumáno pomocí technik termické analýzy: diferenční kompenzační kalorimetrie (DSC) a zejména termogravimetrické analýzy (TGA). Výsledky této práce přinášejí hlubší poznatky o problematice interakce kovů s humifikovanou částí půdní organické hmoty, využitelné k osvětlení problematiky kovových polutantů v životním prostředí a prohloubení žádoucích znalostí procedur jako jsou dekontaminace půdy a remediace.
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