National Repository of Grey Literature 186 records found  beginprevious31 - 40nextend  jump to record: Search took 0.00 seconds. 
Complexes of metals as potential anion receptors
Marečková, Vendula ; Vojtíšek, Pavel (advisor) ; Mosinger, Jiří (referee)
An important class of anion receptors are based on bimetallic complexes with phenols bearing an pendant arms in 2,6-positions. A ligand of this type, 2,6-bis[(N- methylpiperazine-1-yl)methyl]-4-formyl phenol (L1), was prepared using the Mannich reaction. An attempt to prepare a similar compound L2 yield only an oily product. The molecular structure of compound L1 was determinated by X-ray diffraction. Comparison of the L1 structure with similar ones from CCDC showed important influence of the intramolecular H-bond on pendant arms orientations in this type of compounds. Further synthetic exploitation of the aldehyde group (in the position 4) was tested by reaction with 4-nitroaniline. The Shiff base (L3) was obtained but only as an oily substance. Reactions of L1 with Cu(ii) and Zn(ii) perchlorate or acetate produce complexes; the compound [Cu2L1(OH)(OAc)(H2O)]ClO4 (K1) was obtained in a crystallic form. The interactions of anion-bimetallic complex receptor were discused from stereochemical point of view using the structural data from CCDC in the last part of this work.
Synthesis and Use of Transition Metal Complexes with Helical Ligands
Žádný, Jaroslav ; Vojtíšek, Pavel (advisor) ; Kotora, Martin (referee) ; Růžička, Aleš (referee)
The Thesis describes our successful endeavour to develop asymmetric synthesis of functionalized 2H-pyran or 2,7-dihydrooxepine helicene-like compounds in an optically pure form. These helicene surrogates were fully characterized and their use in enantioselective catalysis as chiral ligands, organocatalysts or chiral modifiers was explored. A general method for the preparation of optically pure [5]- and [6]heterohelicenes by asymmetric synthesis is based on highly diastereoselective [2+2+2] cycloisomerization of centrally chiral triynes mediated/catalyzed by transition metal complexes. Stereochemical outcome of the cyclization process is controlled by 1,3-allylic-type strain. This new methodology is highly versatile providing an easy access to chiral ligands, organocatalysts or modifiers in a nonracemic form. Optically pure 2,7-dihydrooxepine [5]helicene-like phosphite ligands were explored in enantioselective allylic amination under catalysis by iridium(I) complexes to reach up to 82% ee. An organocatalysts represented by the optically pure 2H-pyran [5]helicene-like DMAP analogue was synthesized and applied to kinetic resolution of racemic sulfoximines. Finally, various functionalized derivatives of helicenes and helicene-like compounds (azahelicenes, DMAP analogues, (thio)urea derivatives) were...
Electrochemistry of Nitrocalixarenes
Liška, Alan ; Vojtíšek, Pavel (advisor) ; Cibulka, Radek (referee)
In this diploma thesis a detailed investigation of the step-by-step reduction mechanism of cone-mono-, di-, tri and tetranitrocalix[4]arenes (in non-aqueous DMF) is presented. The intramolecular interaction of reducible (and reduced) centers and its consequences for the geometry of the starting molecule was discussed including the character of radicalic intermediates and their spin state. It was found, that the electrochemically generated radical anions of nitrogroups (unlike their starting electroneutral state) can act as ligands. Therefore, a study of complex formation equilibria of cone-tetranitrocalix[4]arenes with alkali metal cations followed. The possible use of a "stereoelectrochemical" approach (the relationship between geometry or conformation of the molecule and its electrochemical data) was demonstrated in describing and explaining conformational and electrochemical differences between two isomeric dinitrocalix[4]arenes. Finally, a new series of 1,3-alt-tetranitrothiacalix[4]arenes was electrochemically characterized and compared with the "classic" calixarene derivatives. Key words: electrochemistry, calixarenes, stereochemistry
Qualitative diagnostics in fitness center
Vojtíšek, Petr ; Bunc, Václav (advisor) ; Hadžega, Tomáš (referee)
Title: Qualitative diagnostics in fitness center. The aim of the diploma thesis: The aim of the theoretical part of the diploma thesis is to summarize the knowledge about the diagnostic entrance test for motion assumptions in fitness and afterwards to help as a study material for people who are interested in being educated in this department. The aim of the practical part of the diploma thesis is to perform the model situation of the diagnostic entrance test in the fitness center carried out in the presence of 10 certificated personal trainers with many years of experience and then with help of semi-structured dialogs and the overall analysis of the concept of the diagnostic, together with an analysis of their experience with diagnostic entrance test in fitness as a whole. Subsequently these data are compared with the theoretical part of this thesis. Objectives: There was used the method of analyzing specialist literature and qualitative research. The qualitative research was done in the fitness center. Results: The outcome of the project supported the theory that the diagnostic entrance test is still not common part of the work of fitness trainer and commonly implemented diagnostics in fitness does not match the theoretical principles of diagnostics, but it is sufficient for the purposes of...
The Life's Alteration Seniors Causes of Transition to Home for Elderly People
Vrtišková, Šárka ; Havránková, Olga (advisor) ; Vojtíšek, Petr (referee)
This thesis is devoted to the elderly and the changes in their lives. The theoretical part deals with the issue of social problems in old age. Briefly describes the age, physical and psychological changes, focusing on changes in social inclusion and the changes in relation to children and grandchildren and also outlined here adaptation. In the research part I through interviews with seniors who are clients of the residence facilities senior home to find out what preceded their decision to enter a home for the elderly. Also, both accept this change and if ever. What aspects of this transition, the hardest for them or, conversely, what they are in this transition most helpful.
Gallium complexes for molecular imaging of bone tissue
Holub, Jan ; Kubíček, Vojtěch (advisor) ; Vojtíšek, Pavel (referee)
Title: Gallium Complexes for Molecular Imaging of Bone Tissue Author: Bc. Jan Holub Department of Inorganic Chemistry, Faculty of Science, Charles University Supervisor: RNDr. Vojtěch Kubíček, PhD. Supervisor's Email address: kubicek@natur.cuni.cz ABSTRACT This thesis is focused on preparing new ligands for selective complexation of gallium, which might serve as potential radiopharmaceuticals for 68 Ga-PET bone imaging. Two new ligands were prepared, combining 1,4,7-triazacyclonone-1,4-diacetic acid macrocyclic skeleton and bis(phosphonate) pendant arm, bound to the remaining free nitrogen atom on the macrocycle. Macrocyclic skeleton is responsible for high kinetic and thermodynamic stability of the Ga3+ complex and the bis(phosphonate) pendant arm insures selective delivery of the complex to the bone tissue. Both new ligands were fully characterized by NMR and mass spectroscopy. Complexation of Ga3+ was studied by 31 P and 71 Ga NMR spectroscopy. Binding to bone tissue was simulated by adsorption of the complexes to hydroxoapatite. Radiochemical experiments including study of 68 Ga complexation kinetics and basic in-vivo experiments including biodistribution studies and PET examination were done in cooperation with Johannes-Gutenberg Universität Mainz in Germany. Data obtained from these experiments were...
Exectrochemical methods as tools for study complex macrocyclic moleculs
Liška, Alan ; Vojtíšek, Pavel (advisor) ; Liška, František (referee)
By means of electrochemical techniques, the electroreduction of polynitrocalix[4]arenes - molecules with multiple redox centers - was investigated and described. Based on interpretation of experimental data and on their correlation with quantum chemical calculations the relationship between structure and redox properties of the title molecules was revealed and discussed. It was shown that the tetranitrocalix[4]arenes involve two different couples of equivalent nitrogroups, what confirms experimentally the pinched shape of the molecule even in solution. The sequence of reduction steps was determined and the corresponding mechanism described. In the first part of the thesis different reduction mechanisms of p-substituted nitroaromates were found in dependence on substitution. It points to an important influence of lower ring substitution on the redox properties of the whole tetranitrocalix[4]arene.
Construction of a new social service for multiple-problem clients
Kocmánková, Dagmar ; Matoušek, Oldřich (advisor) ; Vojtíšek, Petr (referee)
The bachelor thesis "Construction of social service for multi-problem clients" deals with barriers in the use of social services by apparent homeless people, maps their needs and proposes a new low-threshold social service based on obtained data from a qualitative survey. The new social service presents models to overcome barriers, addresses the legislative framework of the service, and proposes a type of organization that could deliver the service. Powered by TCPDF (www.tcpdf.org)
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...

National Repository of Grey Literature : 186 records found   beginprevious31 - 40nextend  jump to record:
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15 VOJTÍŠEK, Petr
3 Vojtíšek, Pavel
15 Vojtíšek, Petr
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