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Activation of ferrocene ligands by sandwich complexes of Group 4 metals
Kout, Matyáš ; Štěpnička, Petr (advisor) ; Vojtíšek, Pavel (referee)
This bachelor thesis deals with synthesis, reactivity and characterization of compounds resulting from the reactions of substituted ferrocene ligands with electron- deficient complexes of group 4 transition metals in oxidation state II with the aim of finding experimental conditions for preparation of complexes containing two metal atoms in one molecule. Reactions were performed under inert atmosphere and the products were crystallized. The obtained crystals were subjected to X-ray diffraction analysis and to NMR spectroscopy in order to elucidate molecular structure of the isolated products. Along the way, instability of the prepared compounds towards air oxygen and moisture has surfaced, though it also led to a discovery of several original compounds. Among these, the molecule containing peroxide ligand bonded to zirconocene fragment is worth noting as a fine example of oxygen molecule activation with low oxidative state complexes of transition metals.
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Polar phosphinoferrocene ligands with hydrocarbyl bridges
Zábranský, Martin ; Štěpnička, Petr (advisor) ; Dostál, Libor (referee) ; Šebesta, Radovan (referee)
A new synthetic route towards methylene-spaced hybrid phosphinoferrocene ligands was developed, making use of a phosphinoferrocene betaine 3-(N,N,N-{[1'-(diphenylphosphino)- ferrocenyl]methyl}dimethylammonium)propane-1-sulfonate (2), that is readily accessible from 1-(diphenylphosphino)-1'-(N,N-dimethylaminomethyl)ferrocene (XIX) via treatment with 1,3-propanesultone. The betaine 2 was reacted with sodium alkylsulfinates (alkyl = methyl, phenyl, 4-tolyl) to afford the corresponding sulfones 4. The coordination chemistry of [1'-(diphenylphosphino)ferrocenyl]methyl(methyl)sulfone (4a) was investigated in its zinc(II) complexes. Surprisingly, only insoluble mixed-metal coordination polymers of the general formula [MZnX3(4a)(MeOH)]n (M/X = Na/Br, K/Br, Na/I) and six-centre complex [Li2Zn2Br6(4a)2(MeOH)4(H2O)] could be obtained. Two isomeric homologues of 1'-(diphenylphosphino)ferrocene-1-carboxylic acid (Hdpf, II), viz. 1'-(diphenylphosphino)ferrocenylacetic acid (HIIa) and 1'- [(diphenylphosphino)methyl]ferrocene-1-carboxylic acid (HIIb), were prepared and their coordination preferences were assessed in their palladium(II) complexes. The palladium(II) complexes were prepared by reacting various (acetylacetonate)palladium(II) precursors with these acids with concomitant release of acetylacetone....
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Synthesis and coordination behaviour of 3-(diphenylphosphino)propanamide
Řežábková, Jana ; Štěpnička, Petr (advisor) ; Havlíček, David (referee)
This bachelor thesis describes the synthesis of 3-(diphenylphosphino)propanamide (compound 1) and subsequent preparation of two palladium(II) complexes with the synthesized phosphinoamide ligand. The coordination behaviour of 3-(diphenyl- phosphino)propanamide is discussed. In complex [PdCl(LNC )(Ph2PCH2CH2C(O)NH2-κP)] (compound 2) the phosphinoamide 1 exhibits P-monodentate coordination, whereas in the cationic complex [Pd(LNC )(Ph2PCH2CH2C(O)NH2-κ2 O,P)]ClO4 (compound 3) it binds as a P,O-chelating bidentate ligand. (LNC = 2-[(dimethylamino-κN)methyl]phenyl-κC1 ). 1 2 3 The ligand was synthesized by base-catalysed addition of diphenylphosphine across the double bond of acrylamide. Both complexes were prepared from [PdCl(LNC )]2 as metal precursor. All substances were characterised by common analytical methods, specifically by NMR spectroscopy, mass spectrometry, infrared spectroscopy and elemental analysis. Crystals of both complexes were obtained and their crystal structure was determined using X-ray crystallography.
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Homologous ferrocene phosphines
Vosáhlo, Petr ; Štěpnička, Petr (advisor) ; Vojtíšek, Pavel (referee)
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.
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Light platinum group metal complexes with a ferrocene N-phosphinoamide
Navrátil, Michal ; Štěpnička, Petr (advisor) ; Gyepes, Róbert (referee)
Title: Light platinum group metal complexes with a ferrocene N-phosphinoamide Author: Bc. Michal Navrátil Department: Department of Inorganic chemistry Supervisor: prof. RNDr. Petr Štěpnička, Ph.D., DSc. Abstract: The aim of this diploma thesis is the preparation of coordination compounds containing ferrocene phosphinoamide FcCONHPPh2 (1, Fc = ferrocenyl), whose preparation was discussed in author's bachelor thesis. Twelve new complexes are described in this thesis, including their characterisation by NMR and infrared spectroscopy, elemental analysis and mass spectrometry. In all cases the crystal structure was determined. Two palladium(II), one rhodium(III) and one ruthenium(II) precursors were used for the preparation of the complexes with each providing three new compounds. A reaction of the precursors with phosphinoamide 1 yielded complexes, in which the phosphinoamide was P-coordinated. This compound was a precursor for the other two complexes. The first one was obtained by a reaction with silver(I) perchlorate producing a cationic P,O-chelate. The other was obtained by a reaction with potassium tert-butoxide resulting in neutral P,O- chelate. All twelve complexes were prepared with optimised yields. Keywords: ferrocene, amides, phosphines, palladium, rhodium, ruthenium, structure elucidation.
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Copper(I) complexes with phosphinonitrile donors
Horký, Filip ; Štěpnička, Petr (advisor) ; Kubíček, Vojtěch (referee)
Title: Copper(I) complexes with phosphinonitrile donors Author: Bc. Filip Horký Department: Department of Inorganic chemistry Supervisor: prof. RNDr. Petr Štěpnička, Ph.D. Abstract: Although coordination compounds with phosphinonitrile ligands are already well known, in the vast majority of these complexes these ligands coordinate as simple P-donors with their cyano groups acting as auxiliary substituents. This led us to synthesize and study a series of Cu(I) complexes with two isomeric phosphinonitrile donors, namely 2-(diphenylphosphino)benzonitrile (Lo ) and 2-(diphenylphosphino)benzonitrile (Lp ), with different ligand-to-metal ratios and possibly characterize further coordination modes offered by these hybrid donors. This work describes the preparation of phosphinonitrile complexes from the aforementioned ligands and simple copper(I) halides (CuX, X = Cl, Br, I), pseudohalides (X = CN) and from [Cu(MeCN)4][BF4]. The products were characterized by nuclear magnetic resonance, infrared spectroscopy and elemental analysis, mass spectrometry, and their solid-state structures were determined by single-crystal X-ray crystallography. In addition, luminescent properties of the Cu(I) complexes were studied and catalytic activity of selected complexes was tested in copper-catalyzed alkyne-azide cycloaddition...
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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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Functional phosphinoferrocene ligands
Škoch, Karel ; Štěpnička, Petr (advisor) ; Grüner, Bohumír (referee) ; Dostál, Libor (referee)
6 Abstract The first part of this Thesis describes the preparation of a novel phosphanyl-ferrocene amine, Ph2PfcCH2NH2 (1; fc = 1,1'-ferrocendiyl) in two steps from the known aldehyde Ph2PfcCHO. An oxime Ph2PfcCH=NHOH was prepared firstly by a condensation reaction, and subsequently treated with Li[AlH4] to give the desired amine. The amine was converted into its more stable hydrochloride salt, Ph2PfcCH2NH3Cl. Derivatization of amine 1 was examined through the preparation of a series of phosphanyl-urea ligands Ph2PfcCH2NHC(E)NR1 R2 . Some of these compounds were also prepared via an alternative method employing reductive amination reaction. These donors and their Pd(II) complexes were evaluated in Pd-catalyzed reaction of arylbromides with K4[Fe(CN)6] in order to prepare corresponding benzonitrile derivatives using aqueous reaction solvents. The reaction proceeds with excellent yields and purity when 1 mol.% of Pd- catalyst is used (at 100 řC for 3 hours), especially for electron-rich bromobenzenes. Substrates with electron-withdrawing substituents react significantly slower and corresponding hydrolytic products (benzamides) are isolated. The coordination properties of phosphanyl-amine 1 were examined towards Cu(I) ions. Thus, reaction of 1 with [Cu(MeCN)4][BF4] provided bis-chelate complex [Cu(1- κ2...
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