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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Homologické ferrocenové fosfiny / Homologous ferrocene phosphines

Vosáhlo, Petr January 2018 (has links)
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.
2

Synthèse et propriétés de ligands de type carbène N-hétérocyclique conjugués à une porphyrines / Synthesis and properties of N-heterocyclic carbene ligands conjugated with porphyrins

Lefebvre, Jean-François 06 December 2010 (has links)
En plus du site de coordination interne classique des porphyrines, il est possible de fonctionnaliser le macrocycle par des sit es de coordination externes. Ce travail de thèse porte sur la fonctionnalisation de deux carbones b-pyrroliques adjacents afin d'obtenir des porphyrines conjuguées avec des ligands de type carbène N-hétérocyclique (CNH).Les CNHs présentent de remarquables propriétés électroniques qui en font aujourd'hui des ligands incontournables en catalyse et en chimie organométallique. L'objectif de ce travail de thèse a été d'étudier l'influence de la porphyrine sur les propriétés électroniques du ligand périphérique CNH, et de moduler les propriétés électroniques et catalytiques de complexe métalliques en fonction des modifications chimiques apportées à la porphyrine, à savoir sa métallation ou la protonation des azotes de la porphyrine base-libre.Dans un premier temps, les différentes méthodes de synthèse développées afin d'obtenir différents sels d'imidazolium conjugués avec le macrocycle porphyrinique sont développées. Ces sels d'imidazolium sont les précurseurs des ligands porphyrine-CNH. Afin d'étudier les propriétés catalytiques de complexes contenant des ligands de type porphyrine-CNH, plusieurs complexes de palladium(II) ont été synthétisés et caractérisés. Les études des propriétés catalytiques de ces complexes testées sur le couplage de Heck ont démontré que de bien meilleures activités catalytiques étaient observées si les porphyrines contiennent un cation métallique. Enfin, les propriétés des ligands CNH ont été étudiées sur des complexes de types (CNH)Rh(COD)X et (CNH)Rh(CO)2X avec X = I ou Cl. / In addition to the usual inner coordination site of porphyrins, it is possible to functionalize the macrocycle by external coordination sites. This PhD thesis is devoted to the functionalization of two neighboring b-pyrrolic carbons in order to obtain porphyrins fused to peripheral N-heterocyclic carbene ligands (NHC).NHC ligands are known to display outstanding electronic properties which render them important ligands in the fields of catalysis and organometallic chemistry. The aim of this PhD work was to study the influence of the porphyrin on the electronic properties of the peripheral NHC ligand, and to modulate the electronic and catalytic properties of anchored metal complexes according to the chemical modifications brought to the porphyrin, ie. its metallation or the protonation of the free-base porphyrin.Firstly, the different synthetic procedures to obtain porphyrins fused to imidazolium rings were developed. These imidazolium salts are the key precursors of the porphyrin-NHC ligands. In order to study the catalytic properties of metal complexes containing porphyrin-NHC ligands, several palladium(II) complexes were synthesized and characterized. The study of the catalystic properties of these complexes showed that better catalytic activities were observed if the porphyrins contain a metal cation. Then, the electronic properties of these NHC ligands were evaluated for (NHC)Rh(COD)X and (NHC)Rh(CO)2X complexes with X = I or Cl.
3

Komplexy 2,6-bis[(N-methylpiperazin-1-yl)methyl]-4-formyl fenolu / Complexes of 2,6-bis[(N-methylpiperazine-1-yl)methyl]-4-formyl phenol

Marečková, Vendula January 2012 (has links)
Thirteen new dinuclear complexes of ligand 2,6-bis[(N-methylpiperazine-1- yl)methyl]-4-formyl phenol (L1) were prepared. Copper(II) and palladium(II) salts were used for the syntheses. Following compounds were prepared: [Cu2L1(CH3COO)2]ClO4, [Cu2L1(CF3COO)2(ClO4)][Cu2L1(CF3COO)2]ClO4, [Pd2L1(CH3COO)3], [Pd2L1(CF3COO)3], [Pd2L1(Cl)4]. These ones should act as anion receptors. The acetates were exchanged for phenylphosphinates in the case of the complex cation [Cu2L1(CH3COO)2]+ and the structure of [Cu2L1(phPO2H)2]ClO4 was obtained. Geometry of coordination shell of Cu2+ - ions in prepared complexes is tetragonal pyramid. The UV-VIS spectroscopy was used for study of interactions in system of the ligand - metal - anion. Interactions between the ligand and metals in oxidation state 2 were observed as well as interactions between the complex [Cu2L1(CH3COO)2]ClO4 and sodium salts.

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