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The study of sulphonated polystyrene nanofabrics with encapsulated sensitizer
Hrdinková, Veronika ; Mosinger, Jiří (advisor) ; Vojtíšek, Pavel (referee)
The diploma thesis is dedicated to the exploitation of sulphonated polystyrene nanofibres as ion exchange nanomaterial. Ion exchange capacity of these nanomaterials has been determined by titration method and AAS. The effect of sulphonation on photophysical, photooxidative and photocytotoxic properties of sensitizer 5,10,15,20-meso- tetraphenylporphyrin (TPP) encapsulated in polystyrene nanofibres has been studied as well. Properties of TPP have been examined with time-resolved spectroscopy, photooxidation of uric acid as substrate and bactericidal tests on Escherichia coli DH5α with pGEM11Z plasmid. It has been discovered that following the sulphonation of the nanofabrics, the encapsulated sensitizer is partly present even in aggregation form. The polystyrene nanofabrics with encapsulated sensitizer keep its bactericidal efficiency also after sulphonation.
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Ants and primary vegetation succession on abandoned industrial-waste deposits
Vojtíšek, Pavel ; Kovář, Pavel (advisor) ; Holec, Michal (referee)
Abandoned industrial-waste deposits (incl. fly ash or tailings ponds) represent very specific and mostly extreme habitat conditions. They offer unique opportunity to study primary succession in cultural landscape. Substrate of the material deposited here shows extreme properties, such as low pH, overheating of the open surface, salinization etc. The aim of this work is to map the colonization of different successional stages of vegetation by ants after years of abandonment of ore-waste deposits in Chvaletice (Eastern Bohemia, CR) and to compare the present state with analogous study made in 2001. Particular aims of both studies (Jarešová 2001, and present study, 2011-12) is to test the influence of ants on vegetation succession. During the years 2011-2012 several prospections were made to record species diversity of ants. On the surface plateau of the sedimentation basin two types of habitats were chosen - the areas with present ant nests and the other areas without them. Each of both types of habitats exhibits different plant species richness: separately the species-area curves were constructed and explained. Three dominant ant species of different size categories present on sedimentation basin were selected for experimental offering of plant seeds, Formica pratensis, Lasius niger, Tetramorium...
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Applied Mineralogy in Forensic Science field
Kotrlý, Marek ; Matějka, Dobroslav (advisor) ; Kopecká, Ivana (referee) ; Vojtíšek, Pavel (referee)
1 ABSTRACT Surprisingly, applied mineralogy plays an important role in the forensic science field. It is the miner- alogical phases which exist in many kinds of materials and traces but also the mineralogical analysis procedures which are often used in the field of so called trace evidence. For purposes of this study, 4 important fields of forensic microanalysis were chosen. These are those fields in which applied min- eralogy is applied and which characterize the width and heterogeneity of the concerned area. Powder X-ray microdiffraction plays quite an important and irreplaceable role not only in the direct phase analysis of substances in mixtures. The author designed, tested and introduced a set for centra- tion and direct check of the analysed surface during micro-diffraction analysis and also experimentally optimised sensing parameters for the different system configuration. A possibility to calculate the size of the nanoparticles (more precisely the size of a mono crystal domain) was tested. XRD methods ap- plication allows refining organic analysis for example in the case of new synthetic drugs. Micro diffrac- tion was also used for the first complex phase analysis of colour layers of the altar in the chapel in the castle of Křivoklát (dated 1480 - 1490). Forensic analysis of soil phases used to be,...
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Synthesis of nanostructured ZnFe2O4 as a sorbent for H2S removal from syngas
Košťálová, Zuzana ; Nižňanský, Daniel (advisor) ; Vojtíšek, Pavel (referee)
The use of sorption properties of materials as sorbents for removing unwanted substances from gasified solid or liquid fuels (coal, oil, natural gas and biomass) in the heating plant industry seems to be more suitable than existing technology. In this diploma work, ZnFe2O4 is studied as a possible sorbent for the removal of H2S from gasified fuel. ZnFe2O4 has been prepared by various methods in the form of nanoparticles and nanocomposites. The prepared samples were characterized by powder X- ray diffraction, electron microscopy, BET measurement and thermal analysis. Further, the sorption activity of the samples was studied with regard to H2S. The results were evaluated with respect to the possible application of the prepared materials in heating plant industry. Keywords: ZnFe2O4, H2S absorption, sol-gel method, sol-gel auto-combustion method, SBA-15.
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Activation of ferrocene ligands by sandwich complexes of Group 4 metals
Kout, Matyáš ; Štěpnička, Petr (advisor) ; Vojtíšek, Pavel (referee)
This bachelor thesis deals with synthesis, reactivity and characterization of compounds resulting from the reactions of substituted ferrocene ligands with electron- deficient complexes of group 4 transition metals in oxidation state II with the aim of finding experimental conditions for preparation of complexes containing two metal atoms in one molecule. Reactions were performed under inert atmosphere and the products were crystallized. The obtained crystals were subjected to X-ray diffraction analysis and to NMR spectroscopy in order to elucidate molecular structure of the isolated products. Along the way, instability of the prepared compounds towards air oxygen and moisture has surfaced, though it also led to a discovery of several original compounds. Among these, the molecule containing peroxide ligand bonded to zirconocene fragment is worth noting as a fine example of oxygen molecule activation with low oxidative state complexes of transition metals.
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Coordination chemistry of pharmaceuticals
Malová, Zuzana ; Lukeš, Ivan (advisor) ; Vojtíšek, Pavel (referee)
Present methods for diagnosis of neurodegenerative diseases are rather limited and in clinical practise are missing. This thesis is focused on utilization of the positron emission tomography using isotope 64 Cu(II). For the project, two contrast agents were proposed containing ligand for Cu (II) coordination and thioflavine T derivative as fluorescent dye, also as a targeting compound. Structure of the thioflavine T derivative was defined by X-ray structural analysis. The selected fluorescent dye has a high affinity for incipient amyloids and, when bound to their structure, has enhanced fluorescent properties. The proposed ligands are tetraazacyclic. The first one is a diamide, where the thioflavin T derivative is part of a macrocyclic ring. The second selected ligand is linked to the thioflavin T derivative via a linker. Key words: complexes; pharmaceuticals; transition metals
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Quantitative analysis by X-Ray powder diffraction
Stachová, Sandra ; Havlíček, David (advisor) ; Vojtíšek, Pavel (referee)
Quantitative analysis methods using X-ray powder diffraction are still highly actual conception in the area of research of modern materials. The Reference Intensity Ratio (RIR) method is used here for quantitative analysis by X-ray powder diffraction of model samples in this bachelor thesis. The model samples are three mixtures of corundum, mullite and calcite. To get diffraction patterns of the mixtures, two different diffractometers are used and their outputs are then compared.
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Functional phosphinoferrocene carboxamides
Schneiderová, Barbora ; Štěpnička, Petr (advisor) ; Vojtíšek, Pavel (referee)
Functionalized amides 3 and 4 were prepared by the reaction of 1'-(diphenylphosphino)ferrocene-1- carboxylic acid (Hdpf) with 2-(diphenylphosphino) ethylamine or 2-N,N'- (dimethylamino)ethylamine. The amides were converted to their respective phosphinsulfides 5 and 6. Addition of MeI to the solution of 6 gave ammonium salt 7 which, after desulfuration with Raney nickel afforded ammonium salt 8. Compounds 3-8 were characterized by NMR and IR spectroscopy and by MS spectrometry. Phosphine sulfides 6 and polar amides 7 and 8 were structurally characterized. Amides 3, 4 and 8 were tested as ligands in Pd-catalyzed Suzuki-Miyaura coupling reaction of phenylboronic acid with 4-bromacetophenone in organic solvent, water and in biphasic system. Amides 3 and 4 and the related amides 1'-(diphenylphosphanyl)-1-[N-{3- (diphenylphosphino)propyl)}carbamoyl]ferrocene(1) and 1'-(diphenylphosphanyl)-1-[N-(3- dimethylaminopropyl)carbamoyl] ferrocene (2) were reacted with [(COD)PdCl2] to afford palladium complexes of the general formula [(L)PdCl2]. These compounds were characterized by NMR and IR spectroscopy and by MS spectrometry and, for selected representatives, also by X-ray diffraction analysis. Keywords: ferrocene, phosphinoamides, palladium, coordination study, catalysis, Suzuki-Miyaura cross-coupling reaction.
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Homologous ferrocene phosphines
Vosáhlo, Petr ; Štěpnička, Petr (advisor) ; Vojtíšek, Pavel (referee)
Title: Homologous ferrocene phosphines Author: Bc. Petr Vosáhlo Department: Department of Inorganic Chemistry Supervisor: prof. RNDr. Petr Štěpnička, Ph.D., DSc. Abstract: This thesis describes the synthesis and coordination behaviour of ferrocene diphosphines derived from 1,1'-bis(diphenylphosphino)ferrocene (dppf). Dppf is one of the most succesful ferrocene ligands, which can be used in various metal-catalyzed reactions. This study aimed to prepare analogous ligands with one dialkylphosphino substituent and one (diphenylphosphino)methyl group. These ligands were oxidized by KSeCN to afford the corresponding phosphinoselenides. The phosphinoselenides were used to assess sigma-donor abilities by measuring the coupling constant 1 JSeP via 31 P NMR spectroscopy. Lastly, the coordination behaviour of these ligands in palladium complexes was studied. The homologous ligands usually formed a mixtures containing a chelate complex and dimeric species with trans- coordinated ligands. Key words: ferrocene, phosphines, homologous ligands, palladium(II) complexes, structure elucidation.
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