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Hydrophospination of activated alkenes catalysed by platinum(O) complexes of functionalised phosphinesWorboys, Kerry January 1993 (has links)
No description available.
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An Exploration of the Structural, Electronic, and Anion Binding Properties of 2-IndolylphosphinesYu, Joanne 26 February 2009 (has links)
2-Indolylphosphines are unique ligands which have the capability for further phosphine modification by introducing substituents on an indolyl nitrogen centre. Substituents can vary in electronics, sterics, chirality, and can contain amino or phosphino groups which result in a multidentate (P,N)- or (P,P)-2-indolylphosphine.
X-ray crystallography was used predominantly to examine and analyze the structural features of 2-indolyphosphines and their metal complexes. While the cone angles could not be determined crystallographically, the sum of the <CPC bond angles provided some information on the steric crowding around a phosphorus atom in selected 2-indolylphosphines.
The symmetric tris-2-(3-methylindolyl)phosphine demonstrated anion binding ability through its three indolyl NH sites. Titrations to a series of selected anions were carried out; it was determined that tris-2-(3-methylindolyl)phosphine binds to these selected anions in a 1 : 1 receptor to anion binding ratio. Crystal structures of the fluoride and acetate complexes confirm the binding stoichiometry, and demonstrate the cooperative interaction of all three indolyl NH sites with the anion guest. Synthetic routes to new anion receptors with three or two indolyl NH donors were explored. The second type yielded a molecular cleft that was used in anion binding studies.
The net basicity of a 2-indolylphosphine was determined through formation of a Ni(CO)3L complex. Net basicity can be tuned by changing the substituents on phosphorus or on an indolyl nitrogen centre. The [Cu(tris-2-(3-methylindolyl)phosphine)(phenanthroline)]BF4 complex is a discrete ion pair complex, exhibiting coordination chemistry at the phosphorus centre of the phosphine, while simultaneously hydrogen bonding through the indolyl NH sites to the BF4- anion. Complexes of the type [Pd(L)Cl(mu-Cl)]2 were analyzed by crystallography and the effect of net basicity on Pd-P bond length examined.
The solid-state structures of (P,N)- and (P,P)-2-indolylphosphines were evaluated. In general, the sum of the <CPC bond angles increased from the parent unfunctionalized 2-indolylphosphine. The metal complexes of (P,N)- and (P,P)-2-indolylphosphines were assessed by crystallography to find possible trends of trans-influence.
Lastly, a tetradentate tripodal ligand was synthesized by furnishing diphenylphosphino substituents on the indolyl nitrogen centres of tris-2-(3-methylindolyl)phosphine. The coordination of the tetradentate tripodal ligand to Pt(II) or Rh(I) resulted in five-coordinate trigonal bipyramidal complexes.
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An Exploration of the Structural, Electronic, and Anion Binding Properties of 2-IndolylphosphinesYu, Joanne 26 February 2009 (has links)
2-Indolylphosphines are unique ligands which have the capability for further phosphine modification by introducing substituents on an indolyl nitrogen centre. Substituents can vary in electronics, sterics, chirality, and can contain amino or phosphino groups which result in a multidentate (P,N)- or (P,P)-2-indolylphosphine.
X-ray crystallography was used predominantly to examine and analyze the structural features of 2-indolyphosphines and their metal complexes. While the cone angles could not be determined crystallographically, the sum of the <CPC bond angles provided some information on the steric crowding around a phosphorus atom in selected 2-indolylphosphines.
The symmetric tris-2-(3-methylindolyl)phosphine demonstrated anion binding ability through its three indolyl NH sites. Titrations to a series of selected anions were carried out; it was determined that tris-2-(3-methylindolyl)phosphine binds to these selected anions in a 1 : 1 receptor to anion binding ratio. Crystal structures of the fluoride and acetate complexes confirm the binding stoichiometry, and demonstrate the cooperative interaction of all three indolyl NH sites with the anion guest. Synthetic routes to new anion receptors with three or two indolyl NH donors were explored. The second type yielded a molecular cleft that was used in anion binding studies.
The net basicity of a 2-indolylphosphine was determined through formation of a Ni(CO)3L complex. Net basicity can be tuned by changing the substituents on phosphorus or on an indolyl nitrogen centre. The [Cu(tris-2-(3-methylindolyl)phosphine)(phenanthroline)]BF4 complex is a discrete ion pair complex, exhibiting coordination chemistry at the phosphorus centre of the phosphine, while simultaneously hydrogen bonding through the indolyl NH sites to the BF4- anion. Complexes of the type [Pd(L)Cl(mu-Cl)]2 were analyzed by crystallography and the effect of net basicity on Pd-P bond length examined.
The solid-state structures of (P,N)- and (P,P)-2-indolylphosphines were evaluated. In general, the sum of the <CPC bond angles increased from the parent unfunctionalized 2-indolylphosphine. The metal complexes of (P,N)- and (P,P)-2-indolylphosphines were assessed by crystallography to find possible trends of trans-influence.
Lastly, a tetradentate tripodal ligand was synthesized by furnishing diphenylphosphino substituents on the indolyl nitrogen centres of tris-2-(3-methylindolyl)phosphine. The coordination of the tetradentate tripodal ligand to Pt(II) or Rh(I) resulted in five-coordinate trigonal bipyramidal complexes.
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Synthesis, structural characterisation and dynamic behaviour of heteronuclear Group IB metal cluster compoundsWilliams, Steven Andrew January 1998 (has links)
No description available.
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Synthesis and catalysis with poly(ethylene oxide)-substituted triphenylphosphinesPinault, Nathalie January 2000 (has links)
No description available.
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A search for bridging-dinitrogen heterobimetallic complexes containing iron and molybdenum or tungstenHelleren, Caroline Anne January 1998 (has links)
No description available.
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Carborane derivatives with electron rich moieties. Synthesis, properties and electronic communicationPopescu, Radu‐Adrian 18 January 2013 (has links)
El treball que es presenta en aquesta tesi és la continuació i ampliació de la feina feta en el nostre grup de recerca en els darrers anys sobre derivats de l’o-carborà que porten grups rics en electrons. L’objectiu global de la tesi és la síntesis i l’estudi teòric d’aquests derivats.
Gairebé tots els compostos sintetitzats en aquest treball s’han obtingut directament a partir de l’o-carborà. La funcionalització dels àtoms de carboni de l’o-carborà es fa en dos etapes. En un primer pas, s’afegeix un agent per arrancar el protons, com són els compostos organolitiats, les amides alcalines, els hidrurs alcalins; i tot seguit, s’afegeix un electròfil (diòxid de carboni, calcogen, halogen, halurs, epòxids, aldehids). Tot i que la substitució dels dos àtoms de carboni del clúster d’o-carborà S’obté pràcticament sempre, la monosubstitució no és gens trivial, perquè sempre ve acompanyada de la disubstitució. Per això, el primer objectiu d’aquest treball ha sigut l’estudi experimental i teòric de la influencia dels dissolvents eterats (Et2O, THF or DME) en la formació dels compostos organolitiats, utilitzant com a plataforma el 1,2-C2B10H12.
Tot i que les fosfines de l’o-carborà són uns dels derivats més estudiats, la investigació de les seves propietats electròniques no ho ha sigut tant. Les carboranilfosfines varen ésser sintetitzades per primer cop fa més de 50 anys, però cap estudi sistemàtic i exhaustiu sobre les reaccions d’oxidació s’havia fet fins ara. Per tant, un altre objectiu d’aquest treball ha sigut l’estudi de les reaccions d’oxidació de les carboranilfosfines amb peròxid d’hidrogen, sofre i seleni; i la seva avaluació com a lligands. Un cop sintetitzats aquests compostos, hem fet un estudi teòric que ha tingut els següents objectius: i) veure la influència dels grups fosfina i fosfina oxidada en els efects electrònics del clúster d’o-carborà; ii) veure els efectes electrònics en les closo-carboranilmonofosfines; iii) veure la labilitat del enllaç fòsfor-calcogen en els monocalcògens dels carboranilmono- i carboranildifosfines; iv) estudiar dels processos de oxidació i degradació; v) estudiar la comunicació intramolecular en les carboranildifosfines aniòniques oxidades.
Un altre grup ric en electrons és el grup formil (-CHO), que una vegada afegit a un clúster d’o-carborà, veure les seves propietats altament modificades. Tot i que el carboranilformaldehid es coneix des de fa temps, hi ha pocs estudis sobre la seva reactivitat. Per tant un altre objectiu d’aquest treball ha sigut l’estudi de la reactivitat d’aquest compost amb la finalitat d’obtenir nous derivats. Per això hem estudiat: i) l’addició nucleofílica al grup carbonílic del derivat litiat de l’o-carborà per obtenir derivats amb múltiples clústers d’o-carborà; ii) la substitució electrofílica dels substrats aromàtics emprant el carboranilformaldehid activat amb la finalitat d’obtenir derivats de l’o-carborà amb propietats luminescents; iii) les reaccions de Wittig i Horner-Wadaworth-Emmons emprant ja sigui el carboranilformaldehid ó els derivats de l’o-carborà amb grups fosfonat i sals de fosfoni.
Per l’últim hem estudiat la síntesis de nous derivats utilitzant com a plataforma la carboranilpiridina. Les reaccions estudiades han sigut: i) la metal·lació de la carboranilpiridina amb complexos de Pd(II), Ir(III), Rh(III) i Ru(II); ii) la síntesis de lligands híbrids carboranilpiridina-fosfina i les seves reaccions de complexació amb Pd(II) i Rh(I); iii) la síntesis de un derivat de la carboranilpiridina que inclou un grup borà; iv) la síntesis de un derivat cobaltabis(dicarballur)-dipiridina. / The work presented in this manuscript is the continuation and extension of the work done in our group during the last years on the carborane derivatives with electron rich moieties. The main objective of this work is to synthesize and to study by computational means new derivatives of carborane with electron rich moieties.
Almost all the compounds synthesized in this work are directly achieved from o-carborane. The direct modification of the C vertexes of the o-carborane is done in two steps. First a deprotonating agent as organolithium compounds, alkali-metal amides or alkali-metal hydrides is added, followed by the addition of a suitable electrophile (carbon dioxide, chalcogens, halogens, halides, epoxides, aldehydes). Although the substitution at the both carbon atoms is always achieved, the monosubstitution is not so trivial, being almost always accompanied by the disubstituted derivative. For that, the first specific objective of this work was to study both experimentally and by computational means the influence of ethereal solvents (Et2O, THF or DME) on the formation of organolithiated compounds, based on the 1,2-C2B10H12 platform.
Though the o-carborane derivatives with phosphorus moieties were the most studied synthetically and some of their properties were exploited, still work has to be done to understand their electronic properties that may ultimate lead to a rationalized design of new derivatives. The carboranylphosphines are known for more than 50 years ago, but no systematic and comprehensive investigation on their oxidation reactions were found in the literature as well as investigations on the electronic properties of these phosphines. For that the second specific objective was the study of the oxidation of carboranylphsophines with hydrogen peroxide, sulphur and selenium and to examine their properties as ligands. Once the synthetic study on the carboranylphosphines and their oxides and chalcogenides was completed, we proceeded with the third specific objective that was the computational study of the carboranylphosphines and their oxides and chalcogenides. The computational study contains: i) the contribution of phosphine and oxidized phosphine moieties to the electronic effects on the o-carborane cluster; ii) electronic effects in closo-carboranylmonophosphines; iii) the lability of the phosphorus-chalcogen bonds in carboranylmono- and carboranyldiphsophine monochalcogenides; iv) the oxidation/degradation processes study; and v) intramolecular communication in oxidized anionic carboranyldiphosphines.
Other moiety that is rich in electrons is the formyl group, that once attached to o-carborane cluster its properties are highly modified. Though the carboranylformadehyde is long known in the literature, studies on its reactivity are rare. For that, the fourth objective was to understand the reactivity carboranylformaldehyde as platform for new derivatives. For that we studied: i) the nucleophilic addition to the carbonyl group with lithated carborane in order to synthesize “confined space” multi-cage compounds; ii) the electrophilic substitution reactions of aromatic substrates with activated carboranylformaldehyde, in order to obtain derivatives with luminescent properties; and iii) the Wittig and Horner-Wadaworth-Emmons reaction using carboranylformaldehyde and carborane containing phosphonates and phosphonium salts.
The fifth specific objective was the study of carboranylpyridine as platform for new derivatives, for which we studied: i) the metalation reaction of carboranylpyridine with Pd(II), Ir(III), Rh(III) and Ru(II); ii) synthesis of carboranylpyridine-phosphine hybrid ligands and complexation reactions of these ligands through Pd(II) and Rh(I) complexes; iii) synthesis of carboranylpyridine-borane derivative; and iv) synthesis of cobalta(bisdicarbollide)-pyridine derivative.
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New approaches for the desing of chiral catalysts. Application in carbonylation reactions.Muñoz Moreno, Bianca Karelia 16 November 2007 (has links)
Actualmente, el interés industrial de los productos carbonilados ha atraído la atención de los científicos hacia el desarrollo de nuevos sistemas catalíticos eficientes. La reacción de alcoxicarbonilación de vinil arenos ha sido considerada una ruta alternativa para la obtención de ácidos 2-aril propiónicos, la clase más importante de antiinflamatorios no esteroides. Por otro lado, los copolímeros de monóxido de carbono y olefinas son materiales de gran interés industrial debido a su aplicación potencial como termoplásticos. El concepto de economía atómica ha influenciado el desarrollo de los procesos catalíticos industriales. El máximo aprovechamiento de los reactivos y la disminución de residuos han hecho de la catálisis un proceso altamente atractivo en el marco de tecnologías de desarrollo sostenible. El conocimiento de los mecanismos operantes en las reacciones de carbonización es de gran importancia para el diseño de nuevos sistemas catalíticos altamente efectivos.Basándose en las consideraciones anteriores, el primer objetivo de esta tesis se ha centrado en el desarrollo de nuevos sistemas catalíticos de paladio y su aplicación en la metoxicarbonilación asimétrica de vinil arenos, con el fin de obtener altas regio- y enantioselectividades, simultáneamente. Un segundo objetivo, ha sido el desarrollo de nuevos catalizadores catiónicos de paladio y el estudio de su actividad catalítica en las reacciones de co- y terpolimerización de CO/etileno/propileno. Para alcanzar el primer objetivo, se ha planteado la exploración de complejos de paladio modificados con fosfinas monodentadas y fosfinas bidentadas. Con el fin de conocer mejor ambos sistemas e identificar algunos intermedios de reacción, se llevó a cabo un estudio de la metoxicarbonilación de estireno bajo condiciones similares a las catalíticas. Para lograr el segundo objetivo, se han sintetizado nuevos catalizadores de paladio catiónicos modificados con difosfinas derivadas de D-(+)-xilofuranosa. Los nuevos complejos se aplicaron en las reacciones de copolimerización de CO/etileno y CO/propileno, así como, en la terpolimerización CO/etileno/propileno. Después de revisar los antecedentes bibliográficos en la introducción y planteados los objetivos, en el Capítulo 2 "Palladium complexes bearing monodentate ligands in asymmetric methoxycarbonylation of vinyl arenes" se presenta la síntesis y caracterización de complejos de paladio modificados con fosfinas cíclicas quirales, tales como, fosfetanos, fosfolanos y fosfepinos. Estos nuevos complejos se aplican en la metoxicarbonilación asimétrica de vinil arenos, mostrando que la actividad decrece a medida que aumenta el número de miembros del ciclo fosforado.En el Capítulo 3 "Palladium complexes bearing bidentate ligands in asymmetric methoxycarbonylation of styrene" se describe la aplicación de complejos de paladio neutros y catiónicos modificados con ligandos bidentados, en la metoxicarbonilación asimétrica de estireno. Los ligandos ultilizados en este capítulo presentan propiedades estéricas y electrónicas diferentes. En términos generales, para los sistemas neutros y catiónicos, la presencia de sustituyentes electroatractores en los grupos fenilos del ligando, tiene una gran influencia sobre la regioselectividad de la reacción hacia el producto ramificado. En el Capítulo 4 "Mechanistic aspects of the methoxycarbonylation of styrene" se discuten algunos aspectos mecanísticos de la metoxicarbonilación de estireno, utilizando complejos de paladio modificados con ligandos monodentados y bidentados. La reactividad de los complejos con los diferentes componentes del sistema catalítico, se llevó a cabo paso a paso y mediante experimentos in situ en condiciones similares a las empleadas en la catálisis.Finalmente en el Capítulo 5 "Cationic palladium complexes bearing xylofuranose-derivative diphosphines in CO/ethene/propene co- and terpolymerisation reactions" se describe la síntesis de una difosfina derivada de la D-(+)-xilofuranosa, así como la síntesis y caracterización de nuevos complejos neutros y catiónicos. Los resultados obtenidos han sido comparados con los complejos análogos modificados con dppp y o-MeO-dppp, con el fin de discutir cómo afectan los efectos electrónicos y la rigidez del ligando en la copolimerización perfectamente alternada. / Nowadays the industrial interest of the carbonylated products has attracted the attention of scientists towards the development of new efficient catalytic systems. The alcoxycarbonylation of vinyl arenes has been considered an alternative route to obtain 2-aryl propionic acids, the most important class of non-steroidal anti-inflammatory drugs. Copolymers formed by carbon monoxide and alkenes are materials of industrial interest due to their potential application as engineering thermoplastics. The concept of atomic economy has influenced the development of industrial catalytic processes. The waste diminishing by the complete conversion of reagents into the desired product in a catalytic process introduce the homogeneous catalysis as an attractive sustainable technology. The knowledge of the carbonylation mechanisms is of great importance for the design of new highly efficient catalytic systems.Based on these considerations, the first objective of this thesis was to develop new catalytic palladium systems and its application in the asymmetric methoxycarbonylation of vinyl arenes, in order to obtain high regio-and enantioselectivities simultaneously. The second objective was to synthesise new cationic palladium complexes and to study the activity in the copolymerisation reaction. To achieve the first objective, palladium complexes modified with monodentate and bidentate phosphine ligands were explored. In order to know more about the influence of the nature of the ligand on the mechanism, a mechanistic study under similar conditions to those used in the catalysis was performed. To achieve the second objective new cationic palladium complexes modified with diphosphine ligands derived from D-(+)-xylofuranose were synthesised. The new complexes were tested in the CO/ethene, CO/propene copolymerisation reaction, as well as in the CO/ethene/propene terpolymerisation process. Chapter 2 "Palladium complexes bearing monodentate ligands in asymmetric methoxycarbonylation of vinyl arenes" shows the use of chiral monodentate cyclic phosphines, such as phosphetane, phospholane and binepine, in the palladium-catalysed asymmetric methoxycarbonylation of vinyl arenes. New neutral palladium complexes are synthesised and characterised by multinuclear NMR spectroscopy. This new complexes were showed a decreased in the catalytic activity when increased the number of the phosphorus membered ring.Chapter 3 "Palladium complexes bearing bidentate ligands in asymmetric methoxycarbonylation of vinyl arenes" describes the synthesis of neutral and cationic complexes bearing bidentate ligands with different electronic and steric properties and its application in the methoxycarbonylation of vinyl arenes. In general terms, it was observed that the presence of electron withdrawing groups in the phenyl moiety of the ligand has an influence on the regioselectivity of the reaction to the branched ester. Chapter 4 "Mechanistic aspects of the methoxycarbonylation of styrene" discusses mechanistic aspects of the methoxycarbonylation reaction. In situ studies are performed under similar conditions to those used in the catalytic studies. The studies are focuses in palladium systems modified with mono- and bidentate ligands, in order to establish comparison between them. The characterisation of some species by NMR spectroscopy is showed.Finally in Chapter 5 "Cationic palladium complexes bearing xylofuranose-derivative diphosphines in CO/ethene/propene co- and terpolymerisation reactions" it was discussed the electronic effects of xylose-derivatives diphosphines ligands in the CO/ethene/propene co- and ter-polymerisation processes. The new diphosphines o-MeO-xylophos is synthesised. A series of new neutral and cationic palladium complexes bearing xylophos and o-MeO-xylophos were synthesised and fully characterised by multinuclear NMR techniques. The catalytic polymerisation reactions were performed in methanol using the cationic complexes and are compared to the reaction catalysed by analogous complexes bearing dppp and o-MeO-dppp to determine the electronic effects and the backbone rigidity on the perfectly alternating copolymerisation.
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Oximas ortopaladadas contendo fosfinas: síntese, caracterização estrutural e estudos biológicos / Orthometallated oximes containing phosphines: synthesis, structural characterization and biological studiesRicci, Gabriela Francini Bozza 14 September 2018 (has links)
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Previous issue date: 2018-09-14 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Ciclopaladados constituem uma classe de organometálicos de grande interesse, sobretudo por suas extensas aplicações em diversas áreas da Química. Dentre os compostos susceptíveis a reação de ortometalação destacam-se as oximas, onde apesar do frequente emprego de complexos ciclopaladados contendo derivados das oximas, como catalisadores ou pré-catalisadores eficientes, pouco se sabe sobre as potencialidades biológicas dos mesmos. Foram sintetizados doze compostos quelatos de paládio inéditos pela clivagem em ponte de compostos do tipo [PdCl(C2,N-oxima)]2 e fosfinas terciárias (L) {C2,N-oxima = acetofenonaoxima ou benzaldeidoxima; L = trifenilfosfina (PPh3), tri(p-toluil)fosfina (tpf), tris-(4-fluorfenilfosfina) (tfpp), tris-(4-metoxifenil)fosfina (tmf), difenil-(p-toluil)-fosfina (dpt) e triciclohexilfosfina (PCy3)}. Os compostos foram caracterizados por análise elementar, análise térmica (termogravimétrica e diferencial), espectroscopia vibracional na região do infravermelho e espectroscopia de ressonância magnética nuclear de 1H, 13C e 31P. As estruturas cristalinas e moleculares de nove compostos foram determinadas por difratometria de raios X de monocristal, onde [PdCl(C2,N-afox)(L)], onde {L = (PPh3), (tfpp), (tmf), (dpt) e (PCy3)} e [PdCl(C2,N-bzox)(L)], em que {L = (PPh3), (tpf), (tfpp) e (PCy3)}. Além disso, cálculos da superfície de Hirshfeld foram realizados para explorar a natureza e as principais contribuições de diferentes contatos intermoleculares na estabilidade do empacotamento do cristal. Experimentos preliminares para determinar o potencial citotóxico dos compostos foram realizados frente a MCF-7 (adenocarcinoma mamário humano), LM3 (adenocarcinoma mamário murino), A549 (adenocarcinoma epitelial de pulmão humano) e MCR5 (fibroblasto de pulmão humano) e ensaios preliminares a respeito da atividade inibitória frente as catepsinas B e L também foram avaliados, sugerindo um possível modo de ação para os compostos obtidos e testados. / Cyclopalladated complexes represent an interesting class of organometallic compounds, mainly for their extensive uses in several areas of Chemistry. Among the organic compounds prone to orthometallation reaction, oximes have attracted considerable attention since their cyclopalladated derivatives have been employed as catalysts in many organic reactions. Despite the intensive work on this area, studies on the biological activity of these compounds remain scarce in the literature. In this context, this work deals with the synthesis, spectroscopic and structural investigation on a series of cyclopalladated compounds of general formulae [PdCl(C2,N-oxime)(L)] (C2,N-oxime = orthometallated acetophenoneoxime (afox) or benzaldehydeoxime (bzox); L = monodentate phosphines). Bridge-splitting reactions between [Pd(C2,N-oxime)(μ-Cl)]2 and phosphines (L = triphenylphosphine (PPh3), tri(p-tolyl)phosphine (tpf), tris(4-fluorophenyl)phosphine (tfpp), tris-(4-methoxyphenyl)phosphine (tmf), diphenyl(p-tolyl)phosphine (dpt) and tricyclohexylphosphine (PCy3)} in a 1:2 ratio, yielded neutral mononuclear cyclopalladated compounds of the type [PdCl(C2,N-oxime)(L)]. The compounds have been characterized by elemental analyses, IR and 1H-, 13C and 31P{1H}-NMR spectroscopies, and thermal analysis TG-DTA. The crystal and molecular structures of the compounds [PdCl(C2,N-afox)(L)] {L = (PPh3), (tfpp), (tmf), (dpt) and (PCy3)} and [PdCl(C2,N-bzox)(L)] { L = (PPh3), (tpf), (tfpp) and (PCy3)} have been determined by single-crystal X-ray diffraction. Hirshfeld surface calculations have been carried out to explore the nature and major contributions of different intermolecular contacts towards crystal packing stability. Preliminary cytotoxic evaluation of the compounds towards MCF-7 (human breast adenocarcinoma), LM3 (murine mammary adenocarcinoma), A549 (human lung epithelial adenocarcinoma) and MCR5 (human lung fibroblast) have been carried out. The ability of the compounds to induce the inhibition of cathepsins B and L have also been evaluated in this work. / CAPES: 1570789
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Synthesis of novel aminomethylphosphine complexesLastra Calvo, Nuria January 2015 (has links)
A new series of aminomethylphosphine ligands incorporating a PCN backbone and a pendant amine were synthesised using a phosphorus Mannich condensation reaction. Their coordination capabilities were investigated with late transition metal centres. Following a procedure well established within our research group, several phosphines were obtained using {P(CH2OH)4}Cl (THPC) in two steps. Firstly, THPC was reacted with various ortho and para anilines to give phosphonium salts P{CH2N(H)R}4Cl (R = C6H5, o-MeC6H4, o-i PrC6H4, o-t BuC6H4, o-FC6H4, o-CF3C6H4, o-{C(Me)=CH2}C6H4, p-MeC6H4, p-i PrC6H4, p-FC6H4 and p-EtC6H4). Secondly, these new salts were reacted with Et3N to obtain the cyclic RN(H)CH2P{(CH2)3(NR)2} phosphines (R = para-substituted anilines) or with KOt Bu to obtain acyclic P{CH2N(H)R}3 phosphines (R = ortho-substituted anilines) and cyclic P{CH2N(R)CH2}2P diphosphines (R = ortho-substituted anilines). Double condensation was observed in the 31P{1 H} NMR of cyclic phosphines RN(H)CH2P{(CH2)3(NR)2} to form {(CH2)3(NR)2}PCH2N(R)CH2P{(CH2)3(NR)2} diphosphines. Some cyclic phosphines were investigated under a wide range of conditions with Ph2PCH2OH giving asymmetric Ph2PCH2N(R)CH2P{(CH2)3(NR)2} diphosphines along with symmetric diphosphines counterparts and other phosphorus coproducts according to 31P{1 H} NMR and MS. A novel bicyclic OP{CH2N(R)CH2}3PO diphosphine (R = p-MeC6H4) was obtained as crystalline solid from the filtrate of the reaction between RN(H)CH2P{(CH2)3(NR)2} and Ph2PCH2OH and it was characterised by X-ray spectroscopy. Attempts to synthesise this diphosphine from P(CH2OH)3 and p-MeC6H4 were unsuccessful. The family of aminomethylphosphine ligands was extended by treating Ph2PCH2OH or CgPCH2OH (Cg = 1,3,5,7-tetramethyl-2,4,8-trioxa-6-phosphaadamantane) with various primary amines to afford R(H)NCH2PR'2 (R' = Cg or Ph). Symmetric Ph2PCH2N(R)CH2Ph2 diphosphines were observed in the 31P{1 H} NMR spectra indicating that phosphines with Ph2P-moiety were more susceptible to undertake a second condensation. Novel asymmetric o-{Ph2PCH2C(H)(CH3)}C6H4N(H)CH2PPh2 diphosphine was synthesised by treatment of o-{C(Me)=CH2}C6H4NH2 with Ph2PH to afford o-{Ph2PCH2C(H)(CH3)}C6H4NH2 followed by condensation of the amino group with Ph2PCH2OH. Analogous o-{CgPCH2C(H)(CH3)}C6H4NH2 phosphine was also obtained. The coordination capabilities of selected compounds was studied with late transition metal precursor such as Pt(II), Pd(II) and Ru(II). Monophosphine compounds acted as Pmonodentate ligands to form square planar cis and trans MCl2L2 (M = Pt and Pd) complexes. However, whereas cyclic ligands RN(H)CH2P{(CH2)3(NR)2} afforded cisMCl2L2, acyclic ligands P{CH2N(H)R}3 afforded trans-MCl2L2 along with cis-PtCl2L2 in some cases. Those phosphines which conducted double condensation adopted a P,Pchelate mode to form a 6-membered M-P-C-N-C-P to afford cis-MCl2L (M = Pt and Pd). More interesting is the rarely observed P,P-bridging mode exhibited by P{CH2N(R)CH2}2P ligands to form homobimetallic cis-(PtCl2L)2 complexes and {RhCl2(η5 -Cp*)}2L complexes. These metal compounds were obtained and characterised by in situ NMR however their structures were further supported by simulated 31P{1 H} NMR and X-ray studies. Asymmetric Ph2PCH2N(R)CH2P{(CH2)3(NR)2} diphosphines coordinated to Pt(II) in a P,P-chelate fashion affording a mixture of cis and trans bis(chelate) (PtL2)Cl2. Complex in trans geometry was isolated and the structure was further supported by X-ray crystallography. The coordination capabilities of the ligands were investigated with Ru(II) metal centre revealing 'piano-stool' structure of the type RuCl2(η6 -p-cymene)L where the monophosphines adopted a P-monodentate mode and {RuCl2(η6 -p-cymene)}2L where the diphosphines adopted a P,P-bridging mode. Preliminary studies with selected Ru complexes were carried out to investigate their potential catalytic activity to trap CO2 by its insertion into the Ru-Cl bond which suggested that the chloride needs to be substituted by a hydride prior the CO2 insertion. Compounds were characterised by spectroscopic techniques and the structure of some phosphines was further supported by X-ray crystallography.
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