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Preparation and Characterization of Graphene Based Hybrid Materials
Hrubý, Jakub ; Novák, Jiří (referee) ; Neugebauer, Petr (advisor)
Grafen v kombinaci s komplexy kovů by mohl poskytnout nové přísutpy v hybridních materiálech založených na grafenové bázi a v oblasti molekulárního magnetismu. Obě témata jsou velmi diskutovaná jako taková, nicméně, výzkumu vedoucího k možnosti jejich míchání není mnoho. Vzorky byly připraveny sonikací grafitu v kapalné fázi, což vedlo k exfoliaci grafenu. Následně byly nadeponovány pomocí modiikované Lagmuirovy– Schaeferovy depoziční metody různé komplexy kovů na substrát pokrytý grafenem. Klíčovým krokem bylo určení vlastností takto připraveného materiálu. Proto byly následně vlastnosti takového hybridního materiálu charakterizovány pomocí vysokofrekvenční elektronové paramagnetické rezonance (angl. HFEPR), rastrovacího elektronového mikroskopu, (angl. SEM), Ramanovou spektroskopií a čtyř bodovou metodou měření odporu. V této práci jsme potvrdili naši presumpci, že je možné vytvořit hybridní materiál smícháním exfoliovaného grafenu s molekulárními magnety pro získání nových magnetických a elektronických vlastností, které by mohly být využity v další generaci detektorů a elektroniky.
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Symmetrical aminophosphinates
Procházková, Soňa ; Kubíček, Vojtěch (advisor) ; Vojtíšek, Pavel (referee)
Title: Symmetrical aminophosphinates Author: Bc. Soňa Procházková Department of Inorganic Chemistry, Faculty of Science, Charles University Supervisor: RNDr. Vojtěch Kubíček, Ph.D. Supervisor's email address: kubicek@natur.cuni.cz ABSTRACT Two types of α-aminophosphinates were prepared and studied: phosphinate analogues of iminodiacetic acid − aminobis(methyl(hydroxymethyl)phosphinic acid) (IDPhm ) and aminobis(methyl(2-carboxyethyl)phosphinic acid) (IDPce ), and bis(aminomethyl- phosphinates) − (hydroxy(fenyl)methylen)bis(aminomethylphosphinic acid) (PheOHABPin) and (methylen)bis(aminomethylphosphinic acid) (ABPin). All prepared compounds were fully characterized (by NMR, MS, elemental analysis). One crystal structure was determined by X-ray singlecrystal analysis. The diphosphinates were synthesized by Mannich type reaction, whereas the bis(aminomethylphosphinates) were prepared by multistep synthesis including reactive silylesters. Compounds were prepared in moderate or good yields Acid-base and coordination properties of ligands were investigated and compared by potentiometric and NMR titrations. The values of protonation constants of aminogroups, which determine stability of complexes, showed surprising results. An extremely low basicity of nitrogen atom was found in diphosphinates. So, these compounds...
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NMR study of solution dynamics of LnIII complexes of monophosphorus H4dota analogues
Svítok, Adam ; Hermann, Petr (advisor) ; Dračínský, Martin (referee)
Lanthanides have several specific properties which cannot be found for other elements in the periodic table. Among various applications of lanthanides, complexes of LnIII ions are used in medicine, e.g., as contrast agents in MRI, as luminescent probes or as radiopharmaceuticals, where their specific properties are important. These complexes must be kinetically inert to prevent release of highly toxic "free" LnIII ions. This requirement is fulfilled with pre-organized ligands such as analogues of H4dota (1,4,7,10- tetraazacyclododecane-1,4,7,10-tetraacetic acid). Many of important properties of LnIII complexes of H4dota, such as relaxivity, isomerism and fluxionality, depend on the solution dynamics of the complexes. However, the knowledge of this solution dynamics is limited for LnIII complexes of H4dota derivatives with phosphonate or phosphinate pendant arms. Recently, a new dynamical process where phosphonate oxygen atoms interchange through a bidentate phosphonate intermediate ("a phosphonate rotation") has been proposed by DFT calculations but unconfirmed experimentally. To prove the process experimentally, solution dynamics of LnIII complexes of monophosphonate and monophosphinate derivatives of H4dota was investigated. Especially, to examine the "P-rotation", 17 O NMR spectroscopy was used...
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Synthesis and studies of modified DNA: (i) development of DNA targeting molecular scissors and (ii) competitive enzymatic incorporation of base-modified nucleotides
Panattoni, Alessandro ; Hocek, Michal (advisor) ; Urban, Milan (referee) ; Fojta, Miroslav (referee)
In the first part of this work, a series of site-specific artificial metallonucleases (AMNs) was developed conjugating clamped-phenanthroline (Clip-Phen) copper complexes to triplex- forming oligonucleotides (TFOs). Several synthetic routes were explored for the synthesis of the TFO-AMNs hybrids, all sharing a copper-catalyzed alkyne-azide cycloaddition (CuAAC) reaction as the key step. As a consequence, building blocks for enzymatic or chemical synthesis of oligonucleotides (ONs) containing clickable groups, or already conjugated to the Clip-Phen ligand via CuAAC, were prepared. Two new alkynyl-linked nucleoside-5'-O-triphosphates (dNTPs) were designed and developed in order to obtain an efficient polymerase incorporation of clickable alkynyl-tethers into ONs and, at the same time, enhance the efficiency of CuAAC reactions on modified DNA. The relative 3'-O- phosphormaidites were also prepared in order to insert the same alkynyl-linkers into ONs via solid-phase synthesis. The AMN was linked at the 5'- or 3'-ends or in the middle of the TFO stretch, using diverse likers. The hybridization of all the synthesized TFOs with a target DNA duplex was studied. Finally, an extensive study of cleavage efficiency and specificity of the TFO-AMN conjugates towards the target DNA was performed, exploring the...
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Preparation and Characterization of Graphene Based Hybrid Materials
Hrubý, Jakub ; Novák, Jiří (referee) ; Neugebauer, Petr (advisor)
Grafen v kombinaci s komplexy kovů by mohl poskytnout nové přísutpy v hybridních materiálech založených na grafenové bázi a v oblasti molekulárního magnetismu. Obě témata jsou velmi diskutovaná jako taková, nicméně, výzkumu vedoucího k možnosti jejich míchání není mnoho. Vzorky byly připraveny sonikací grafitu v kapalné fázi, což vedlo k exfoliaci grafenu. Následně byly nadeponovány pomocí modiikované Lagmuirovy– Schaeferovy depoziční metody různé komplexy kovů na substrát pokrytý grafenem. Klíčovým krokem bylo určení vlastností takto připraveného materiálu. Proto byly následně vlastnosti takového hybridního materiálu charakterizovány pomocí vysokofrekvenční elektronové paramagnetické rezonance (angl. HFEPR), rastrovacího elektronového mikroskopu, (angl. SEM), Ramanovou spektroskopií a čtyř bodovou metodou měření odporu. V této práci jsme potvrdili naši presumpci, že je možné vytvořit hybridní materiál smícháním exfoliovaného grafenu s molekulárními magnety pro získání nových magnetických a elektronických vlastností, které by mohly být využity v další generaci detektorů a elektroniky.
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Symmetrical aminophosphinates
Procházková, Soňa ; Kubíček, Vojtěch (advisor) ; Vojtíšek, Pavel (referee)
Title: Symmetrical aminophosphinates Author: Bc. Soňa Procházková Department of Inorganic Chemistry, Faculty of Science, Charles University Supervisor: RNDr. Vojtěch Kubíček, Ph.D. Supervisor's email address: kubicek@natur.cuni.cz ABSTRACT Two types of α-aminophosphinates were prepared and studied: phosphinate analogues of iminodiacetic acid − aminobis(methyl(hydroxymethyl)phosphinic acid) (IDPhm ) and aminobis(methyl(2-carboxyethyl)phosphinic acid) (IDPce ), and bis(aminomethyl- phosphinates) − (hydroxy(fenyl)methylen)bis(aminomethylphosphinic acid) (PheOHABPin) and (methylen)bis(aminomethylphosphinic acid) (ABPin). All prepared compounds were fully characterized (by NMR, MS, elemental analysis). One crystal structure was determined by X-ray singlecrystal analysis. The diphosphinates were synthesized by Mannich type reaction, whereas the bis(aminomethylphosphinates) were prepared by multistep synthesis including reactive silylesters. Compounds were prepared in moderate or good yields Acid-base and coordination properties of ligands were investigated and compared by potentiometric and NMR titrations. The values of protonation constants of aminogroups, which determine stability of complexes, showed surprising results. An extremely low basicity of nitrogen atom was found in diphosphinates. So, these compounds...
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Příprava modifikovaných nukleosidů, nukleotidů a oligonukleotidů nesoucích komplexy kovů
Vrábel, Milan ; Hocek, Michal
Series of modified nucleosides and oligonucleotides bearing metal complexes were synthetized. Palladium catalyzed aqueous-phase cross-coupling reactions were used as key step in the synthesis of modified metallo-labeled nucleosides, nucleotides and oligonucleotides. The corresponding Fc modified dNTPs were good sustrates for DNA polymerases and were efficiently incorporated to DNA by primer extension (PEX). The modified nucleic acids are applicable as tools in bioanalysis.
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