National Repository of Grey Literature 58 records found  beginprevious49 - 58  jump to record: Search took 0.00 seconds. 
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.
Synthesis of 1,4-phosphonic and phosphinic acid derivatives of cyclen
Bárta, Jiří ; Kotek, Jan (advisor) ; Vojtíšek, Pavel (referee)
Title: Synthesis of 1,4-phosphonic and phosphinic acid derivatives of cyclen Author: Bc. Jiří Bárta Department: Department of Inorganic Chemistry, Faculty of Science Supervisor: Doc. RNDr. Jan Kotek, Ph.D. Supervisor's e-mail adress: Abstract This thesis is focused on synthesis of diphosphonic and diphosphinic derivatives of cyclen at 1,4 positions as potential MRI contrast agents. Preparation of 1,4-dibenzylcyclen was optimized in a gramme scale for synthesis of derivatives mentioned above. 1,4-dibenzyl-7,10-bis(diethylphosphonomethyl)cyclen was prepared in a gramme scale. It's fully hydrolyzed and monoester forms were prepared. 1,4-bis(diethylphosphonomethyl)cyclen was synthesized. It's fully hydrolyzed and monoester forms were synthesized. 1,4-dibenzyl-7,10- bis(phosphinomethyl)cyclen was synthesized. The carboxylic function in ester form was attached on diesterphosphonic derivative of cyclen. Altogether 8 derivatives in positions 1,4 and 7,10 of cyclen was prepared, mostly in a gramme scale and with a high yield. All compounds were characterized by NMR and MS. Key words: cyclen, phosphonate, phosphinate, sythesis, MRI
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.
Synthesis of alkylphosphinic acids
Procházková, Soňa ; Vojtíšek, Pavel (referee) ; Kubíček, Vojtěch (advisor)
The preparation of methylphosphinic acid and (3-terc-butoxy-3-oxopropyl)phosphinic acid using reaction between bis(trimethylsilyloxy)phosphine (BTSP) and iodomethane or tert-butyl acrylate was investigated. BTSP was generated in situ from ammonium phosphinate and hexamethyldisilazane. Simultaneously, the preparation of BTSP using N,O-bis(trimethylsilyl)acetamide was optimilized. The effect of conditions of the alkylation and addition reactions on the yield of monosubstituted and disubstituted phosphinic acids was examined. Furthemore, the preparation and properties of the BTSP-borane adduct and its possible employment in H-phosphinic acid syntheses were explored KEYWORDS: Organophosphorus synthesis, silylesters, borane adducts.
Industrial deposits: Are they habitats of threatened or invasive species?
Vojtíšek, Pavel ; Tonika, Jaroslav (referee) ; Kovář, Pavel (advisor)
There was made many deposits of industrial slags on our landscape during second half of 20th century. Many of deposits were abandoned without recultivation because of missing or inadequate legislation. Often very extreme habitat enables scientific research. Deposits and their surface are developing and stabilizing because of primary succession. This study works with two types of deposits: ash-slag and ore-washery sedimentation basins. During succession many plant species are introduced onto basin plateau. Ecosystem contains many unoccupied habitats and for invasive plant species it's easy to introduce into these free habitats. Contrariwise the ecosystem should pose a refuge point for ecological important plant species. In this study are worked data about total vegetational cover of vascular plants on 21 sedimentation basis (12 ash-slag and 9 ore-washery). From the data package were sorted out plants demonstrably invasive, potentially invasive and endangered plants. An occurrence of the species was compared with the type and age of sedimentation basin. Key words: Sedimentation basin, invasive plant, potentially invasive plant, endangered plant, life strategy, management

National Repository of Grey Literature : 58 records found   beginprevious49 - 58  jump to record:
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11 Vojtíšek, Petr
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