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Polydentate aminodiphosphinates
Böhmová, Zuzana ; Kubíček, Vojtěch (advisor) ; Vojtíšek, Pavel (referee)
Two linear aminodiphosphinates (H3L1 , H5L2 ) and one cyclic aminodiphosphinate (H2L3 ) were prepared and studied. Newly prepared compounds were characterized by NMR, MS and EA (elemental analysis). Acid-base and coordination properties of ligands were studied. Protonation constants and stability constants of complexes with Zn2+ , Ni2+ and Cu2+ metal ions were determined by potentiometry. Keywords Ligands, dissociation constants, potentiometry, phosphinates, complexes.
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
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.
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...
Synthesis and catalytic properties of phosphinoferrocene guanidine
Bárta, Ondřej ; Štěpnička, Petr (advisor) ; Vojtíšek, Pavel (referee)
Title: Synthesis and catalytic properties of phosphinoferrocene guanidine Author: Ondřej Bárta Institution: Faculty of Science, Charles University in Prague, Department of Inorganic Chemistry Supervisor: prof. RNDr. Petr Štěpnička, Ph.D. Polar phosphine ligands proved to be useful in homogeneous and biphasic catalysis. Most of these phosphines bears anionic functional groups. On the other hand, functionalization of phosphines by cationic substituents is still quite uncommon, although these functional groups possess properties that could improve catalytic performance of the catalyst. In this regard, nitrogenous bases are particularly attractive due to their inherent basicity and the ability to enter into hydrogen bonding interactions. This thesis describes the synthesis of a novel ferrocene-based phosphine functionalized with guanidine moiety, viz. N-[1′-(diphenylphosphino)ferrocenylmethyl]guanidine (3). This compound was obtained by direct guanylation of 1′-(diphenylphosphino)- 1-(aminomethyl)ferrocene (2) (see scheme). Compound 3 was further used to prepare palladium complexes including the unusual zwitterionic complex [PdCl3(3H)]. The molecular structures of the prepared complexes were determined by X-ray diffraction analysis. Catalytic properties of phosphine 3 and complex [PdCl3(3H)] were...

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