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Ferrocene stibane ligands
Antala, Jakub ; Štěpnička, Petr (advisor) ; Gyepes, Róbert (referee)
5 Title: Ferrocene stibane ligands Author: Jakub Antala Department: Department of Inorganic Chemistry Supervisor: prof. RNDr. Petr Štěpnička, Ph.D., DSc. Abstract: This diploma thesis reports a study into the coordination properties of ferrocene phosphino-stibine Cy2PfcSbPh2 (LCy, Cy = cyclohexyl, fc = ferrocene-1,1'-diyl). Complexes with various transition metals were prepared (RuII , RhIII , PtII , PdII , AuI ), where the ligand binds in monodentate, bridging or chelating mode. Ruthenium(II) and rhodium(III) complexes were prepared from precursors with π-coordinated arene ligands, whereas [MCl2(η2 :η2 cod)] (M = Pd, Pt; cod = 1,5-cyclooctadiene) precursors were used to prepare palladium(II) and platinum(II) complexes and synthesis of gold(I) complexes started from [AuCl(tht)] (tht = tetrahydro- thiophene). In addition, the thesis describes the reactivity of ferrocene phosphino-stibine Ph2PfcSbPh2 (LPh). Specifically, it focuses on the preparation of chalcogenides Ph2P(E)fcSbPh2 (E = O, S, Se) and the corresponding stiborane derivatives Ph2P(E)fcSbPh2(O2C6Cl4) (E = void, O, S, Se), in which the stiborane center bears tetrachloropyrocatechol substituent, which makes it Lewis acidic and potentially prone to behave as an acceptor of electron pair from the Ph2P(E) moiety. The presence of this interaction was...
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Synthesis of gold(I) biscarbene complexes with ferrocenyl substituents
Franc, Michal ; Štěpnička, Petr (advisor) ; Růžička, Aleš (referee)
Title: Synthesis of gold(I) biscarbene complexes with ferrocenyl substituents Author: Bc. Michal Franc Institution: Faculty of Science, Charles University in Prague, Department of Inorganic Chemistry Supervisor: prof. RNDr. Petr Štěpnička, Ph.D., DSc. Abstract: Coordination-activated isocyanides attracted attention after it was found that carbene complexes could be readily prepared from them by addition reactions of protic nucleophiles. Carbenes have attracted much interest in recent years as a new class of ligands for transition metals and catalysis. Their advantage is their ability to stabilize catalytically active centers and thereby accelerate catalytic processes. This work presents the preparation of biscarbene gold(I) complexes with ferrocene substituents via addition reactions of amines. The starting material was a bis(isocyanoferrocene)gold chloride, which was the reaction of amines to Fischer-type protic carbenes by reactions with amines. Further, bis(isocyanoferrocene)gold(I) perchlorate was prepared and from it bis(isocyanoferrocene)gold(I) complex was synthesised by addition reaction of mofoline. All newly prepared compounds (Scheme 1), except compound 1, were characterized by NMR (except insoluble compound 5), IR spectroscopy, elemental analysis, MS and their solid state structure was...
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Ferrocene acylphosphines
Vosáhlo, Petr ; Štěpnička, Petr (advisor) ; Čermák, Jan (referee) ; Horáček, Michal (referee)
6 Abstract The Thesis is aimed at the synthesis of novel ferrocene-based acylphosphines of the type FcC(O)PR2 and R1 2PfcC(O)PR2 2 (Fc = ferrocenyl, fc = 1,1'-ferrocendiyl), evaluation of their electron-donating capabilities and steric demands. The impact of these features was scrutinized by further coordination and catalytical studies. First, a series of monodentate acylphosphine ligands FcC(O)PR2 was synthesized (PR2 = diphenylphosphino [PPh2], dicyclohexylphosphino [PCy2], di(1-adamantyl)phosphino [PAd2] a 1,3,5,7-tetramethyl-2,4,6-trioxa-8- phosphaadamantyl [PCg]), which underwent oxidation by elemental selenium to give corresponding phosphine selenides used to probe their electron-donating capabilities via measuring 1 JPSe coupling constant. Then, chlorogold complexes were prepared from these ligands to evaluate their catalytic activity in gold-catalysed hydration of alkynes and cyclization of N-propargylbenzamide. Second, the model compound FcC(O)PPh2 was extensively studied as a ligand in palladium(II) complexes. The ligand was smoothly ortho-metallated by Na2[PdCl4] to form chloro-bridged palladium(II) dimer, which reacted with P-, N- and C-donors under cleavage to give monopalladium complexes. One of these complexes, containing trimethylphosphine auxiliary ligand, was alkylated with organometallic...
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Polar ferrocene phosphines with nitrogen-containing linkers
Navrátil, Michal ; Štěpnička, Petr (advisor) ; Dostál, Libor (referee) ; Horáček, Michal (referee)
Title: Polar Ferrocene Phosphines with Nitrogen-Containing Linkers Author: RNDr. Michal Navrátil Supervisor: prof. RNDr. Petr Štěpnička, Ph.D., DSc. Abstract: This Ph.D. thesis describes three series of bridged ferrocene phosphines derived from aminoferrocene. The first series is comprised of homoannular α- and β-aminophosphines 1-3. The α-aminobis(phosphine) 1 was synthesized from aminoferrocene and (diphenylphosphino)- methanol via phospha-Mannich reaction in a 87% yield. This product was formed regardless of the reaction stoichiometry. Later, ligand 1 was utilized as a ligand for group 10 and 11 metal ions. With group 10 metal precursors, the ligand afforded five different square-planar complexes [MX2(1-κP)] (M/X = Ni/Cl, Pd/Cl, Pd/Br, Pd/I, Pt/Cl). In contrast, the complexes of group 11 metals showed varied geometry around the metal centre, ranging from a linear arrangement in [Au2Cl2(1-κP)], cyclic structure in [Au2(1-κP)2][SbF6]2 and tetrahedral arrangement in [M(1-κP)2][X] (M/X = Cu/BF4; Ag/SbF6; Au/SbF6). The cyclic voltammetry measurements suggested that Fe(II) oxidation is the first oxidation process. The attribution was corroborated by DFT calculations of 1 and [PdCl2(1-κP)]. To obtain the analogous monophosphine 2, aminoferrocene was N-methylated prior to the phospha-Mannich reaction. Subsequent...
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Coordination properties of a 2-(diphenylphosphino)guanidine ligand
Leitner, Zdeněk ; Štěpnička, Petr (advisor) ; Lamač, Martin (referee)
Title: Coordination properties of phosphinoguanidine ligand Author: Bc. Zdeněk Leitner Institution: Faculty of Science, Charles University in Prague, Department of Inorfanic Chemistry Supervisor: prof. RNDr. Petr Štěpnička, Ph.D., DSc. Polar phosphine ligands have found use in variety of homogenous and biphasic catalytic processes. In the past, extensive research has been performed also on cationic phosphines, namely phosphinoguanidinium salts. However, neutral phosphinoguanidines have been mostly neglected and their coordination chemistry has not been described to a satisfactory extent, even though the combination of soft phosphorous and harder nitrogen Lewis base could exhibit interesting properties, mainly hemilabile coordination, as well as protonation-controlled nitrogen coordination. These properties could have a positive impact on catalytical performance of this ligand in systems, which benefit from hydrogen bonding or the presence of basic guanidine group. The aim of this work was to study coordination properties of an earlier prepared ligand L and the corresponding phosphinoguanidine salt L·HCl in reactions with Group 11 metal precursors. New compounds were characterized, and their crystal structures were determined. In addition to conventional compounds, an uncommon dimeric complex...
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Complexes of 1,4,7-triazacyclononane phosphinate derivatives
Lebruška, Viktor ; Kubíček, Vojtěch (advisor) ; Štěpnička, Petr (referee)
Phosphorus pendant arms accelerate the complexation of gallium(III) ions with macrocyclic chelators, which is crucial parameter in labelling by the radioisotope 68 Ga and their use in positron emission tomography (PET). In this thesis, new chelators for the selective complexation of gallium(III) ions were designed. Two chelators derived from the TACN macrocycle were prepared, namely: 1,4,7-triazacyclononane-1-methyl-methylene- bis(phosphinic) acid (H2L1 ) and 1,4,7-triazacyclononane-1-methyl-methylene- bis(phosphinato)-4,7-bis(methyl-phosphinic) (H4L2 ). The acidobase properties of the H2L1 were investigated using potentiometric and NMR titrations. Complexes of H2L1 with Ni(II), Cu(II), Zn(II) and Ga(III) were investigated using potentiometric titrations, which showed the high stability of these complexes. The solid-state structures of the Cu-L1 and Zn-L1 complexes were determined by X-ray diffraction. Complexation of the radioisotope 68 Ga(III) was studied for chelators H2L1 , H4L2 and for several related chelators with phosphorus pendant arms. The complexation study showed that chelators with the methylene-bis(phosphinate) pendant arm and some other phosphorus chelators derived from the TACN macrocycle accelerate complexation of gallium(III) ions. Using Dynamic PET scanning and ex-vivo...
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Synthesis of annelated ferrocene compounds by C-H activation
Varmužová, Věra ; Štěpnička, Petr (advisor) ; Hrdina, Radim (referee)
Title: Synthesis of annelated ferrocene compounds by C-H activation Author: Věra Varmužová Department: Department of Inorganic chemistry Supervisor: prof. RNDr. Petr Štěpnička, Ph.D., DSc. Abstract: This diploma thesis disrcibes the synthesis of two annelated ferrocenes, ferroceno[c]isoquinoline (9) and benzo[f]ferroceno[c]isoquinoline (13). Starting compound used for their synthesis, [(methylsulfonyl)amino]ferrocene, was prepared from aminoferrocene. During the synthesis of compound 9, the reaction sequence was optimized, which includes the nucleophilic substitution, C-H activation and aromatization. Compound 13 was prepared similarly using the optimized reaction conditions An intermediate prepared during the synthesis of compound 9, 1,2-dihydro-2-(methylsulfonyl)ferroceno[c]isoquinoline (7), was additionally used to prepare cationic ruthenium complex 14, wherein it links as a η6 -ligand via its benzene ring. For compounds 7, 9 and 14 UV-VIS absorption spectra were recorded and compared. Key words: ferrocene, annelated ferrocenes, C-H activation, organometallic chemistry
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Synthesis of gold(I) carbene complexes from isocyanoferrocene
Harmach, Petr ; Štěpnička, Petr (advisor) ; Gyepes, Róbert (referee)
Title: Synthesis of gold(I) carbene complexes from isocyanoferrocene Author: Petr Harmach Department: Katedra anorganické chemie Supervisor: prof. RNDr. Petr Štěpnička, Ph.D., DSc. Abstract: The objective of this bachelor thesis was the synthesis of gold(I) carbene complexes. These complexes were synthetised from a newly prepared gold(I)-isocyanoferrocene complex and also directly from isocyanoferrocene. Carbene complexes were obtained from primary and secondary amines, and therefore complexes contain disubstituted or trisubstituted diaminocarbene moieties. All newly prepared complexes were characterized by NMR spectroscopy, mass spectrometry, elemental analysis and infrared spectroscopy. The structures of the majority of the prepared complexes were confirmed by single-crystal X-ray diffraction analysis. Key words: isocyanides, ferrocene, carbenes, gold(I) complexes
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Catalytic testing of polar amidophosphines
Šrámková, Helena ; Štěpnička, Petr (advisor) ; Veselý, Jan (referee)
Catalytic testing of polar amidophosphines: abstract A series of new nine arylruthenium complexes [(aryl)RuCl2(L)] was studied in isomerisations of allylic alcohols to carbonyl compounds. The best reaction conditions were found. The best solvent and reaction temperature were chosen. The best amount of catalyst and the best base and its amount were chosen too. In these conditions, the catalysts were tested for four substituted allylic alcohols. It was proven that these catalysts isomerise readily simple allylic alcohols, but not substrates that is highly substituted.
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