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1
Chamayou, Anne-Christine [Verfasser], and Christoph [Akademischer Betreuer] Janiak. "Chiral metal-Schiff base complexes = Chirale Metal-Schiff-Base-Komplexe." Freiburg : Universität, 2011. http://d-nb.info/1115490567/34.
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Jensen, Svend Borup. "Schiff base calixarenes." Thesis, University of the West of Scotland, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.246345.
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Four different synthetic routes to the sub-target, the p-tert-butylcalix[4lethylamine (6a) from thep-tert-butylcalix[4]arene (1a) have been examined. The best one was a 5-step synthesis, which gave an overall yield of65%. p-tert-Butylcalix[6]ethylamine (6b) and p-tert-butylcalix[8]ethylamine (6c) were synthesised from their respective p-tertbutylcalixarenes by the same route as the p-tert-butylcalix[4]ethylamine (6a). The three different amines (compound (6a), (6b) and (6c)) were used in 14 different Schiff -base type reactions which resulted in six Schiff-base compounds which were fully characterised by NMR, IR, FAB-ms and UV-vis. Insertion studies of the Schiff-base compounds along with template synthesis of the Schiff-base compounds were also attempted. The uptake of solid metal salt by the Schiff-base compounds in solution was examined by UV-vis spectroscopy. One of the Schiff -base compounds synthesised was the ferrocenecarboxaldehyde Schiff-base calix[4]arene (22a). An electrochemical analysis of this compound was undertaken to assess whether if it could be used as a sensor for metal ions. Molecular modelling of the Schiff-base compound and a crystal structure ofp-tert-butylcalix[4]ethylnitrile (8) are also presented in the thesis
3
Boden, Britta Nicole. "Investigations of highly conjugated macrocycles and polymers for aggregation and chemical sensing." Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/269.
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With the goal of developing Schiff base macrocycles with conjugation extended over multiple aromatic rings, new phenanthrene and triphenylene-containing bis(salicylates) were synthesized. A convenient route to 3,6,9,10-tetraalkoxy-2,7-diiodophenanthrene was developed. This compound has been found to be a useful precursor for Pd-catalyzed cross-coupling reactions.
Macrocycles were synthesized by Schiff base condensation of the phenanthrene and triphenylene precursors. Reaction of smaller phenanthrene and triphenylene bis(salicylates) with 1,2-dialkoxy-4,5-phenylenediamine afforded macrocycles in poor yield and purity, but formation of the macrocycle was confirmed by mass spectrometry. Condensation of larger phenanthrene ethynylene bis(salicylates) with phenylenediamines formed [3+3] Schiff base macrocycles in good yield and could be purified through recrystallization. These two large macrocycles were weakly luminescent, and showed decrease in intensity of emission in solution over time. Addition of nitroaromatic compounds to solutions of the macrocycles caused quenching of luminescence, but Stern-Volmer constants could not be determined. One of the macrocycles aggregates in solution and shows some order in the solid state. Association constants for self-assembly of this macrocycle in chloroform were determined, and aggregation was found to be enthalpically driven and entropically disfavoured. Both large macrocycles can complex metals, but low solubility prevents thorough characterization of the metal complexes.
Phenanthrene-containing poly(phenyleneethynylene)s (PPEs) and poly(phenylenevinylene)s (PPVs) were synthesized via the Sonogashira and Heckcouplings, respectively. The PPEs had high molecular weight and both polymers were extremely luminescent with OF = 70% for the PPE and OF = 59% for the PPV. These polymers show potential for use in solar cells and nitroaromatic sensors
.
Dithienylsalphen monomers were made using 4-(2-thienyl)salicylaldehyde and 5-(2-thienyl)salicylaldehyde. These monomers were coordinated to Ni(II), Cu(II) and vanadyl, and tested for electropolymerization. Conjugated dithienylsalphen monomers polymerize poorly, while non-conjugated dithienylsalphen monomers form good films through electropolymerization. Ultraviolet-visible spectroscopy confirmed extended conjugation in N,N '-phenylenebis(4-(2-thienyl)salicylideneimine).
4
Leung, Alfred Chi Wook. "Conjugated schiff base-type metal-containing polymers." Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/15889.
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The work in this thesis describes the synthesis and characterization of a series of
conjugated polymers containing Schiff base transition metal complexes. High molecular weight poly(salphenyleneethynylene)s (PSPEs) were synthesized using the Sonogashira-Hagihara protocol and they were characterized using nuclear magnetic resonance spectroscopy and gel permeation chromatography. Their optical properties were investigated by UV-vis and
fluorescence spectroscopies. PSPEs containing Zn saiphen moieties were found to exhibit strong aggregation that is facilitated by the presence of Zn to O interactions, and it was discovered that
the polymers interact with various Lewis bases to undergo aggregation and deaggregation. New ladder-type conjugated polymers, as well as a series of model compounds that are representative
of the repeating units of the polymers, were synthesized using Schiff base condensation methods. The electronic and magnetic properties of these ladder-polymers were studied using cyclic voltammetry, electron paramagnetic resonance spectroscopy, and magnetic susceptibility measurements.
5
Wojciechowski, Paul E. "Electrochemistry of oxorhenium(V) Schiff base complexes." Thesis, Georgia Institute of Technology, 1985. http://hdl.handle.net/1853/25988.
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Najera, Blanca A. "Schiff base macrocyclic ligands and their complexes." Thesis, University of Sheffield, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.301827.
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Armstong, Douglas Charles. "Schiff base and related complexes of iron." Thesis, Imperial College London, 1985. http://hdl.handle.net/10044/1/37621.
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Ruwwe, Christian. "Volumetrische 3D-Modellierung aus unkalibrierten Freihandaufnahmen /." Tönning ; Lübeck Marburg : Der Andere Verl, 2008. http://d-nb.info/990884430/04.
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Provençal, Alexandre. "Synthetic strategies for self-assembled schiff-base macrocycles." Thesis, University of British Columbia, 2009. http://hdl.handle.net/2429/6048.
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Schiff-base macrocycles have interesting properties that could be used in new materials such as chemical sensors, catalysts and discotic liquid crystals. Triangular [3+3] Schiff-base macrocycles, for example, have been extensively studied in the MacLachlan group. However, few examples of [4+4] Schiff-base macrocycles have been reported. A square [4+4] Schiff-base macrocycle requires a precursor with the appropriate geometry such as compound 18. Synthesis of compound 18, however, proved to be problematic because of the formation of isomers, poor solubility and low yields. To avoid these issues, compound 36 was synthesized by Sonogashira coupling and was characterized by ¹H NMR spectroscopy, IR spectroscopy and HR-EI-MS. Reaction between compounds 36 and 37 led to the formation of an insoluble red solid. Although the characterization of this solid by NMR spectroscopy was not possible, MALDI-TOF data suggested that this solid contained the [4+4] Schiff-base macrocycle as the major product.
A new synthetic approach to compound 11, widely used for the formation of [3+3] Schiff-base macrocycles, was devised. The overall yield is about 10% higher than the original synthesis of compound 11. Aside from the higher yield, this synthetic approach has other advantages over the previous one such as it does not require a large excess of reagents or expensive chemicals, all steps can be achieved on large scales and little purification between each step is required. All new intermediates were characterized by ¹H NMR spectroscopy, ¹³C NMR spectroscopy, IR spectroscopy and HR-EI-MS.
10
Jiang, Jian. "Studies of supramolecular chemistry through Schiff-base chemistry." Thesis, University of British Columbia, 2010. http://hdl.handle.net/2429/27809.
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This thesis describes the synthesis, characterization, and host-guest studies of a series of Schiff-base macrocycles. New [2+2] Schiff-base macrocycles were prepared by Schiff-base condensation. These macrocycles were shown to be wide-mouthed supramolecular hosts that can include organic cations such as pyridinium, paraquat and ammonium derivatives. A new kind of donor-acceptor-donor 3-in-1 complex was obtained in solution by combining macrocycle, cyclobis(paraquat-p-phenylene) and tetrathiafulvalene.
Variations of these [2+2] Schiff-base macrocycles were prepared by modifying the substituents of the diformyl diol unit. In this way naphthalene-based macrocycles that undergo keto-enamine tautomerization were synthesized. These macrocycles can also combine with organic cations to form host-guest complex. The naphthalene-based [2+2] macrocycles can form lyotropic liquid crystals in chloroform and 1,2-dichloroethane. From the polarizing optical microscopy, it is proposed that the mesophases are lyotropic nematic liquid crystals based on a bilayer structure. A further study of these macrocycles shows that the host-guest complex can also form a lyotropic liquid crystalline phase.
Covalently-linked macrocycles with isosceles triangle shapes were prepared by Schiff-base condensation. The molecular isosceles triangles proved to also be supramolecular hosts for pyridinium and ammonium cations, based on ¹H NMR, 2D-ROESY NMR, and mass spectrometry studies.
In addition to the Schiff-base macrocycles, conjugated Schiff-base containing oligomers were synthesized via Gilch polymerization methods. The oligomers were characterized by gel permeation chromatography (GPC), thermogravimetric analysis (TGA) and UV-Vis spectroscopy. For further proof of the oligomeric structure, a model compound was prepared by the Wittig reaction.
11
Black, Daniel. "Studies on binuclear Schiff-base compartmental ligand complexes." Thesis, University of Nottingham, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363560.
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Branscombe, Neil D. J. "Studies on binuclear compartmental Schiff-base thiolate complexes." Thesis, University of Nottingham, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299550.
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Givaja, Gonzalo. "Schiff-base polypyrrolic complexes of late transition metals." Thesis, University of Nottingham, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.430509.
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Ryan, Sara Jane. "Dinuclear Schiff base complexes as models for metallobiosites." Thesis, University of Sheffield, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.301587.
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Toner, Andrew Joseph. "Titanium-aluminium and titanium-alkyl Schiff base complexes." Thesis, Manchester Metropolitan University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.361566.
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Ikenaga, Mamiko. "Die Ghettogeschichten von Hermann Schiff und Hermann Blumenthal /." Frankfurt am Main : P. Lang, 2001. http://catalogue.bnf.fr/ark:/12148/cb390137265.
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Machado, Vanderlei Gageiro. "Catalise cationica na hidrolise de bases de Schiff." reponame:Repositório Institucional da UFSC, 1992. http://repositorio.ufsc.br/xmlui/handle/123456789/76823.
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Dissertação (mestrado) - Universidade Federal de Santa Catarina. Centro de Ciencias Fisicas e MatematicasMade available in DSpace on 2012-10-16T22:10:59Z (GMT). No. of bitstreams: 0Bitstream added on 2016-01-08T17:55:49Z : No. of bitstreams: 1 90932.pdf: 1736571 bytes, checksum: 9b5e57becaa70fc482282dcd39d1c725 (MD5)
A reação de hidrólise das bases de Schiff N-benzildenoanilina, 4-metóxi-N-benzilidenoanilina, 2-metóxi-N-benzilidenoanilina e 2-(2-etoxi)etóxi-N-benzilidenoanilina foi estudada a 25oC, na presença de sais de metais alcalinos e alcalino-terrosos em diversas concentrações. A força iônica foi mantida constante no meio etanólico aquoso (88%) através da adição de tetrafluoroborato de tetrabutilamônio. Os resultados foram explicados em termos de três fatores: a) o efeito inibitório da complexação do íon metálico com o átomo ligado ao anel; b) o efeito provocado pela associação do cátion com o átomo de nitrogênio imínico; c) o efeito templato, envolvendo a associação do íon metálico com os átomos de oxigênio da cadeia lateral.
18
Edwards, David Ryan. "Towards liquid crystalline [3 + 3] Schiff-base macrocycles." Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/31612.
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Conjugated Schiff-base macrocycles are interesting compounds of interest as platforms for catalysis, the preparation of novel synthetic ion channels and potentially as porous or tubular discotic liquid crystals. The preparation of organic macrocycles is typically low yielding, with polymerization competing with cyclization; the use of imines derived from the condensation of an aldehyde and an amine provides a means by which to conduct cyclizations under thermodynamic control and thereby improve yields. The use of difunctional aldehydes and amines allows for the formation of macrocycles in high yields without the need for high-dilution conditions. Two highly substituted dialdehydes also bearing phenolic and aikyl functionalities were prepared by several routes in an effort to obtain macrocycle precursors. These precursors were characterized and subsequently employed to prepare [3+3] Schiff-base macrocycles with a large number of appended aikyl and alkoxy substituents in hopes that they would display discotic liquid crystallinity.
A series of highly substituted [3+3] Schiff-base macrocycles was prepared and characterized by ¹H NMR, ¹³C NMR, UV-Vis, and IR spectroscopies in addition to MALDI-TOF mass spectrometry. The thermal properties of these macrocycles were also examined, and they were not found to display liquid crystalline mesophases either by differential scanning calorimetry or polarizing optical microscopy. A crystal structure of one of the macrocycles was obtained and was found to display structural features not previously observed in related macrocycles.Science, Faculty of
Chemistry, Department of
Graduate
19
Archibald, Stephen James. "Complexes of tripodal and macrocyclic Schiff base ligands." Thesis, University of Edinburgh, 1995. http://hdl.handle.net/1842/14781.
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The synthesis, structures and physical properties of tripodal and macrocyclic Schiff base ligands and their complexes are described. All ligands are synthesised by the condensation of amines with 2,6-diformyl- or 2,6-diacetyl-phenols. The synthesis of a novel dodecadentate tripodal Schiff base ligand, L1H3, is described. Reaction of L1H3 with Ln(ClO4)3 where Ln=La, Pr gives complexes of the form [Ln(L1H3)(H2O)](CIO4)3 and where Ln=Y, [Y(L1H3)](CIO4)3. The single crystal X-ray structures of L1H3 and complexes are described. L1H3 reacts with Gd(CIO4)3 in the presence of Cu(CIO4)2 and N,N-diisopropyl-ethylamine resulting in hydrolysis of the acetal functionality to give a complex of the nonadentate tripodal ligand L5H3, [Gd(L5H3)(H2O)2](CIO4)3, the single crystal X-ray structure of which is described. A similar reaction occurs with Ni(CIO4)2, giving [Ni(L5H3)](CIO4)2, The X-ray structure of which is also described. The preparation of L-H3, a related tripodal nonadentate ligand, is described and the structure determined by single crystal X-ray analysis. Complexes prepared by reaction with M(CIO4)2, M=Ni, Zn, are of the form [M(L2H3)](CIO4)2 and the single crystal X-ray structures show the two complexes are isostructural. The Schiff base macrocycle [L3H4](PF6)2 reacts to form [Cu2L3(CH3CO2)]Br preferentially in the presence of La(CIO4)3 and Cu(CH3CO2)2. The single crystal X-ray structure is described. A template condensation of 2,6-diformyl-4-methylphenol and tris(2-amino-ethyl)amine around yttrium(III) yields a complex of the macrobicyclic ligand. L6H3, [Y(L6H3)(H2O)2](CIO4)3, the single crystal X-ray structure of which is described. [La(L6H3)(H2O)](CIO4)3 was further reacted with Ni(CIO4)2 in the presence of N,N-diisopropylethylamine to form the heterobimetallic complex [LaNi(L1)(H2O)](CIO4)2, the structure of which was confirmed by single crystal X-ray analysis. Preliminary magnetic studies on the complex [GdNi(L1)](CIO4)2 indicate a weak ferromagnetic coupling between the metals.
20
Marques, Fernando Mattiucci. "Catalisadores de rutênio coordenados à base de Schiff para polimerização via metátese." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/75/75135/tde-28112013-112154/.
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Essa pesquisa tem como meta estudar a atividade catalítica de complexos do tipo [RuCl2(PPh3)x(BS)] a partir de reações entre [RuCl2(PPh3)3] e os compostos do tipo Base de Schiff (BS) do tipo R1N=CHR2 onde os grupos R1 = cicloexil, fenil ou sec-butil, para aplicações em reações de polimerização via metátese por abertura de anel (ROMP) de norborneno (NBE). As reações foram realizadas na presença de etildiazoacetato (EDA) e os resultados dos complexos foram comparados em relação às características dos polímeros isolados em função da temperatura e do tempo de reação. Os complexos foram caracterizados por análise elementar CNH, espectroscopia na região do infravermelho e UV-Vis, RMN (31P; 1H) e voltametria cíclica. Os poliNBE apresentaram um σc = 0,41 determinado por RMN 13C. Experimentos realizados por 60 minutos a 25 °C na razão [NBE]/[Ru] = 5000 mostraram que o complexo [RuCl(PPh3)2(Ph)(IminCy)] formou 95% de poliNBE, enquanto que o complexo [RuCl(PPh3)2(Ph)(IminPh)] sintetiza 81,4% de NBE. Para o complexo [RuCl(PPh3)2(Ph)(IminBu)] sua atividade em ROMP para o NBE foi de 70,3%. Assim foi comparado a reatividade entre os ligantes Cy, Ph e Bu. Nas mesmas condições, apenas o complexo [RuCl(PPh3)2(Ph)(IminCy)] obteve melhora significativa no rendimento a 50 °C. Foram investigados também os efeitos de agentes promotores como ácido, sal e luz para a viabilização das reações de ROMP.This research aims to study the activity of[RuCl2(PPh3)x(BS)] complexes by means of [RuCl2(PPh3)3] and Schiff base ligands (BS) R1N=CHR2where R1= cyclohexil, phenil and sec-butil groups, in order to catalyze ring opening metathesis polymerization (ROMP) reactions of norbornene (NBE). The reactions occur in presence of etyldiazoacetate (EDA) and was investigated according to the temperature and the time reaction. The complex was characterized by CNH elemental analysis, infrared, UV-vis spectra, NMR (1H; 31P) and cyclic voltametry. The polymer showed σc = 0,41 by NMR (13C). The experiments performed for 60 minutes at 25 °C with the ratio [NBE]/[Ru] = 5000 showed that [RuCl(PPh3)2(Ph)(IminCy)] complex obtained 95% of polyNBE, while that [RuCl(PPh3)2(Ph)(IminPh)] complex yielded 81,4% of NBE. However, the [RuCl(PPh3)2(Ph)(IminBu)] provided 70,3% of polyNBE. Under same conditions, only [RuCl(PPh3)2(Ph)(IminCy)] complex showed significant changes at 50°C. In addition, promoters agents with acids, salts and light were investigated with the aim at making the ROMP reactions feasible.
21
Tancu, Yolanda. "Monofunctional and dendritic schiff base (N, N′) ruthenium carbene." Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/5261.
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Crook, B. V. "A study of homobinuclear and heterobinuclear Schiff base complexes." Thesis, University of East Anglia, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376081.
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Choudhary, Nosheen Fatima. "The chemistry of oxovanadium(IV) tetradentate Schiff base complexes." Thesis, University of Sussex, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.244319.
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Jakubovic, David Andrew. "Metal complexes of water-soluble multidentate Schiff base ligands." Thesis, Imperial College London, 1989. http://hdl.handle.net/10044/1/47487.
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Chen, Zhengyu. "Disparate symmetries in head-to-tail Schiff-base macrocycles." Thesis, University of British Columbia, 2017. http://hdl.handle.net/2429/60618.
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Two new Schiff-base macrocycles (called campestarenes) with 5-fold symmetry were prepared with bulky triphenylsilyl and triisopropylsilyl substituents. A single crystal structure of one campestarene showed an almost flat conformation of campestarenes are in their extreme enol-imine form. Tautomerization within the campestarene between the enol-imine and keto-enamine form was investigated by variable-temperature NMR and UV-vis spectroscopy. It was found that the molecule displays strong solvent- and temperature-dependent tautomerization that leads to large changes in color. These results were supported by computational investigations that showed the possibility of tautomerization between keto-enamine form and enol-imine form. The experimental studies showed the relative permittivity of solvents has a large influence on the relative stability of different campestarene tautomers in solution.
Some methyl/phenyl substituted campestarene precursors were prepared for macrocyclization of methyl/phenyl substituted campestarenes. Different synthetic conditions were tested to facilitate the formation of campestarens. One phenyl substituted campestarene was synthesized under acid condition.
Two new Pt₃ Schiff-base macrocycles with 3-fold symmetry were synthesized following a head-to-tail approach. Computational investigations showed an almost flat conformation of Pt₃ macrocycles. Aggregation of Pt₃ macrocycles in solid state was studied by MALDI-TOF, TEM and PXRD. It was found that Pt₃ macrocycles displays nanotubular structures due to aggregation. Aggregation of Pt₃ macrocycles in solution was investigated by variable-temperature 1D NMR and 2D NMR. The experimental results showed aggregation of Pt3 macrocycles at both high and low temperatures. Errata: http://hdl.handle.net/2429/60786Science, Faculty of
Chemistry, Department of
Graduate
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Gallant, Amanda Jane. "New [3+3] Schiff-base macrocycles and their complexes." Thesis, University of British Columbia, 2006. http://hdl.handle.net/2429/30870.
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A series of conjugated [3+3] Schiff-base macrocycles containing both a central
crown ether-like pocket and three tetradentate N[sub 2]O[sub 2] binding sites were prepared and
investigated. The formation mechanism was investigated through the synthesis and study
of macrocycle fragments. Further understanding of the macrocycle conformations and
dynamics was obtained through computational studies.
A monoreduced macrocycle where one of the six imines has been reduced was
obtained as a by-product of macrocycle formation. Reactivity studies and deuterium
labeling investigations revealed that the selective reducing agent is likely a
benzimidazoline. This intermediate is generated in situ during the formation of the nonreduced
macrocycle and with macrocycle reduction is converted to a stable
benzimidazole unit.
Upon addition of small cations, the conjugated Schiff-base macrocycles assemble
into tubular structures. Spectroscopic and mass spectrometric studies have shown that the
cations bind to the crown ether-like centre of the macrocycle and induce aggregation to
form structures composed of alternating cations and macrocycles.
With the addition of seven equivalents of Zn[sup 2+] or Cd[sup 2+] to these fully conjugated
macrocycles surprising heptametallic complexes were obtained. Here, the trimetallated
macrocycle is first formed (with metal ions bound to the three N[sub 2]O[sub 2] pockets) and then
this templates the formation of a [M[sub 4]O][sub 6+] cluster that caps the cone-shaped macrocycle.
NMR studies indicated that these zinc complexes dimerize under certain solvent conditions forming capsule-like structures resembling cavitands used in host-guest
chemistry.
Variations of these [3+3] Schiff-base macrocycles were prepared by modifying
the substituents of the diformyl diol unit. In this way naphthalene-based macrocycles
were prepared. Studies on a series of related model compounds revealed that the ketoenamine
isomer is stabilized in these macrocycles rather than the enolimine isomer as
observed in the analogous phenyl-based macrocycles.Science, Faculty of
Chemistry, Department of
Graduate
27
Oshin, Kayode. "Synthesis, characterization, and application of chiral Schiff-base complexes." Diss., Kansas State University, 2011. http://hdl.handle.net/2097/8541.
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Doctor of PhilosophyDepartment of Chemistry
Christopher J. Levy
This work examines the synthesis of novel chiral Schiff-base complexes derived from (1R,2R)-cyclohexanediamine and (R)-[1,1’-binaphthalene]-2-2’-diamine structural backbones with quinoline, isopropyl-quinoline, and benzoquinoline structural side-arms. We incorporated some degree of flexibility in the ligands and complexes so they can accommodate the sterics of different substrates during a catalytic reaction. We successfully achieved this by reducing the imine bond in the ligands to the corresponding amine bond. Therefore, the successful reduction and metallation of some of these ligands to give structures of different symmetries is reported. We had difficulty reducing ligands with the binaphthalene backbone but were able to partially reduce the ligand through a one-pot reaction with a zinc(II) salt and NaBH4. The complete 1H NMR assignments of the complexes reported in this thesis serve as a valuable tool for use in the characterization of future complexes. The complete NMR characterization of compounds reported is a complex process because they are polycyclic aromatic systems and the coupling network similarity in different parts of the molecule usually results in severe overlap of their 1H resonances. To overcome this impediment, we took advantage of various 2D-NMR techniques (COSY, NOESY, ROSEY, HSQC, and HMBC) along with other 1D-NMR experiments (1H HOMODEC, 1H, and 13C) to completely assign the desired complexes. Subsequently we also studied the coordination chemistry of several meal cations with our ligand system with the goal of obtaining single stranded monhelices. The potential use of some of the complexes in the area of NMR discrimination and kinetic resolution of racemic mixtures was examined and shown to be promising. Several NMR experiments were conducted using the racemic olefins 3-buten-2-ol and 1-penten-3-ol to demonstrate the discriminating power of our silver(I) complexes. We discovered that sterics play an important role in this resolution experiment and the bulky nature of our complexes affect the overall efficiency of the NMR discriminatory process as it diminishes the contact between the reactive metal center and the olefins involved. Temperature also plays a vital role in the chiral recognition of racemic olefins as we examined the ideal temperature needed to reduce the various dynamic processes that take place in solution at room temperature.
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Sichermann, Wolfgang. "Zur Simulation und Vorhersage extremer Schiffsbewegungen im natürlichen Seegang." Aachen Shaker, 2008. http://d-nb.info/99248085X/04.
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AGUSTIN, DOMINIQUE. "Bases de schiff et coordinences non usuelles du germanium, de l'etain et du plomb : (base de schiff)m(ii), (base de schiff)m = x et (base de schiff)m n = ml m (m = ge, sn, pb ; x = s, se, n-sime 3 ; m = w, cr, fe et mn ; n = 1, 2)." Toulouse 3, 1999. http://www.theses.fr/1999TOU30162.
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Ce travail concerne l'etude d'especes organometalliques stables des types >m, >m = y (y = o, s, se, n-sime 3) et (>m) nm (m : metal de transition) a metal 14 a coordinence non usuelle. Le premier chapitre est une mise au point bibliographique concernant les basses coordinences stables des types > m et (> m) nm (m = ge, sn, pb). Le deuxieme chapitre concerne la synthese et l'etude physicochimique des nouvelles especes divalentes l 2m (m = ge, sn, pb ; l 2 = base de schiff). Les donnees spectroscopiques soulignent la coordination intramoleculaire n-m-n. Des reactions de cycloaddition et la structure rx de l'adduit (salen)sn-3,5-di-tert-butyl-1,2-benzoquinone sont presentes. Des insertions d'aldehydes ou de clivage par des acides organiques et des chlorures d'acides conduisent, a partir de (salen)m, a de nouveaux composes divalents heteroleptiques. Le troisieme chapitre concerne les complexes (salen)m nm(co) 6 - n (m = ge, sn, pb ; m = cr, w, n = 1, 2) 2. Les structures rx indiquent le caractere double de la liaison sn = m. Les complexes (salen)m = m(co) 5 (m = ge, sn ; m = cr, w) conduisent, par des reactions de cycloaddition et de substitution de ligands, a de nouvelles especes a enchainement p-w-sn ou a des composes trimetalles sn-m-sn (m = cr, w). Le quatrieme chapitre decrit les complexes (salen)m = mncp(co) 2 (m = ge, sn, pb), (salen)sn = fe(co) 4 et leurs structures rx. Le caractere double de la liaison (salen)m-ml n, du au caractere -donneur et au fort caractere -accepteur de (salen)m, est demontre par l'obtention de la plus courte liaison sn-mn connue dans (salen)sn = mn(cp)(co) 2. La position axiale de (salen)sn dans la structure de (salen)sn = fe(co) 4 demontre que (salen)sn est plus -donneur que -accepteur vis-a-vis du fer. Le cinquieme chapitre traite de la reactivite des especes divalentes (salen)m vis-a-vis d'oxydants conduisant a de nouvelles especes insaturees de type (salen)m = y (m = ge, sn ; y = s, se, n-sime 3) ; certains aspects de leur reactivite sont egalement presentes. La derniere partie concerne des transferts de ligands entre (salen)sn et des composes halogenes (bf 3. Me 2o, cp 2ticl 2, nicl 2. Dppe, pcl 3, tbupcl 2, cl 3p = x (x = o, s)) conduisant a de nouveaux composes lineaires ou cycliques a ligand salen du bore, du titane, du nickel et du phosphore (neutres ou cationiques).
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Potgieter, Kim Carey. "Complexes of the ReO³⁺/Re(CO)₃cores with multidentate N,O-Donor chelates." Thesis, Nelson Mandela Metropolitan University, 2009. http://hdl.handle.net/10948/1225.
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This study investigates the coordination modes of multidentate N,O-donor ligands toward the [ReVO]3+ and fac-[ReI(CO)3]+ cores. The reactions of trans-[ReOX3(PPh3)2] (X = Cl, Br) with 4-aminoantipyrine (H2pap) were studied, and the complexes cis-[ReX2(pap)(H2pap)(PPh3)](ReO4) were isolated. The X-ray crystal structures show that both complexes display a distorted octahedral geometry around the central rhenium atom, and are mirror images of each other. The ligand pap is coordinated monodentately through the doubly deprotonated amino nitrogen as an imide, and H2pap acts as a neutral bidentate chelate, with coordination through the neutral amino nitrogen and the ketonic oxygen. The attempted synthesis of the potentially hexadentate Schiff base ligand 1,2-bis(2-{(Z)- [(2-hydroxyphenyl)imido]methyl}phenoxy)benzene from the condensation reaction of 2- (2-((2-aminophenoxy)methyl)benzyloxy)benzenamine and salicylaldehyde produced the zwitterion derivative (H2ono) of 2-{(Z)-[2-(hydroxyphenyl)imino]methyl}phenol. The tridentate Schiff bases (Z)-2-(2-aminobenzylideneamino)phenol (H3onn) and (Z)-2-(2- (methylthio)benzylideneamino)phenol (Hons) were prepared in a similar manner. The reaction of H2ono with trans-[ReOBr3(PPh3)2] surprisingly led to the isolation of the rhenium(III) complex [ReBr(PPh3)2(ono)], in which ono acts as a dianionic tridentate ligand. The reaction of H3onn with trans-[ReOBr3(PPh3)2] produced the imidorhenium(V) complex salt [ReBr(PPh3)2(onn)]Br, in which onn is coordinated as a trianionic tridentate imidoiminophenolate. The reaction of Hons with [Re(CO)5Br] led to the further decomposition of the Hons ligand, and the rhenium(I) product fac- [Re(CO)3(ons)(Hno)] (Hno = 2-aminophenol) was isolated, with ons coordinated as a monoanionic bidentate chelate (with a free SCH3 group), and Hno present as a neutral monodentate ligand with coordination through the amino nitrogen atom. Abstract Nelson Mandela Metropolitan University vi The reactions of the potentially hexadentate ligand N,N’-{ethane-1,2- diylbis[nitrilomethylidenebenzene-1,2-diyl]}bis(2-aminobenzeneimine) (H2ted) with rhenium(V) starting materials resulted in the decomposition of the H2ted molecule to give different coordinated multidentate ligands coordinated to the rhenium(V) centers. In the reaction of H2ted with trans-[ReOBr3(PPh3)2] in ethanol, the highly unusual ‘3+3’ complex cation [Re(tnn)(Htnn)]Br2 was isolated, in which tnn is coordinated as a tridentate imido-imino-amine, and Htnn is present as a tridentate monoanionic amidoimino- amine chelate (H2tnn = N-(2-aminophenylmethylidene)ethane-1,2-diamine). With trans-[ReO2(py)4]Cl as starting material, the neutral complex [ReO(dne)] was found, in which the tetradentate chelate dne acts as a triamido-imine. The reaction of cis- [ReO2I(PPh3)2] with H2ted led to the formation of the monocationic complex salt [ReO(ane)]PF6, with ane acting as a tetradentate dianionic diamidodiimine (H2ane = N,N’-bis[(2-aminophenyl)methylidene] ethane-1,2-diamine). The seven-coordinate rhenium(III) complex cation [Re(dhp)(PPh3)2]+ (H2dhp = 2,6-bis(2- hydroxyphenyliminomethyl)pyridine) was isolated as the iodide salt from the reaction of cis-[ReO2I(PPh3)2] with H2dhp in ethanol and as the perrhenate salt from the reaction of trans-[ReOBr3(PPh3)2] with H2dhp in methanol. Both products result from a disproportionation reaction with perrhenate also being produced in the process. The complex fac-[Re(CO)3(H2dhp)Br] was prepared from [Re(CO)5Br] and H2dhp in toluene, where the H2dhp ligand acts as a neutral bidentate NN-donor chelate. The metal is coordinated to three carbonyl donors in a facial orientation, to a neutral imino nitrogen, a pyridinic nitrogen and a bromide.
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Parra, Diego Noé David. "Construção e otimização de uma plataforma sensorial eletroquímica a base de nano-metalopolimero poli[Ni(Salpn)]." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/75/75135/tde-22052018-133439/.
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Metalopolimeros são considerados excelentes materiais para a construção de eletrodos modificados quimicamente devido ao fato de apresentar propriedades essenciais, como por exemplo, uma alta atividade eletrocatalítica, eletroluminescia, aplicações na área da eletroquímica e eletroanalítica em atividades de eletrocatálise, quimioresistores, fotoeltrocatálise e desenvolvimento de sensores, respectivamente. Alguns complexos de metais de transição contendo Bases de Schiff como ligantes exibem propriedades eletrônicas não convencionais, que têm sido extensivamente estudadas para a aplicação no desenvolvimento de modelos sintéticos aos compostos biológicos como as metaloproteínas e metaloenzimas. O intuito principal desta tese foi o estudo da síntese, otimização e aplicação do nano-metalopolimero à base de poli[Ni(Salpn)] como plataforma sensorial eletroquímica, visando a obtenção de melhoras significativas em determinadas propriedades estruturais, catalíticas, dentre outras. Essas propriedades dependem, não somente do comportamento molecular, mas também, dos efeitos dos possíveis rearranjos estruturais devido às interações intermoleculares. Desta forma, foi construído e estudado o desempenho eletroquímico de uma plataforma sensorial à base de eletrodos constituídos com filmes poliméricos, sendo possível a avaliação de suas aplicações na determinação de substâncias com importância analítica nas áreas clínica, farmacêutica e ambiental. No âmbito que tange a síntese e caracterização do complexo Ni(Salpn), foi possível confirmar por meio de técnicas de caracterização de materiais a eficiência do métodos utilizados. Analogamente, a eletropolimerização foi realizada com sucesso, obtendo nano-filmes com espessura aproximada 110 nm com ótima atividade eletroquímica. A avaliação na aplicação do nano-metalopolímero poli[Ni(Salpn)] apresentou uma excelente resposta frente ao H2O2, possuindo uma rápida resposta, um intervalo linear de 49,9 a 1480 μmol L-1, com limite de detecção de 7,68 μmol L-1 e sensibilidade de 24,05 μÅ mmol-1, viabilizando assim a construção de uma plataforma sensorial viável, rápida, precisa e exata, com a finalidade de resolução de problemas analíticos.Metalopolymers are considered to be excellent materials for the construction of chemically modified electrodes due to the fact that they present essential properties, such as high electrocatalytic activity, electroluminescence, electrochemical and electroanalytical applications in electrocatalysis, chemoresistors, photoeltrocatalysis and sensor development, respectively. Some transition metal complexes containing Schiff Bases as binders exhibit unconventional electronic properties which have been extensively studied for application in the development of synthetic models for biological compounds such as metalloproteins and metalloenzymes. The most aim of this thesis was to study the synthesis, optimization and application of nano-metallopolymer based on poly [Ni(Salpn)] as an electochemical sensorial platform, aiming at obtaining significant improvements in certain structural, catalytic properties, among others. These properties depend not only on molecular behavior but also on the effects of possible structural rearrangements due to intermolecular interactions. In this way, the electrochemical performance of a sensorial platform based on electrodes made with polymer films was constructed and studied, being possible the evaluation of its applications in the determination of substances with analytical importance in the clinical, pharmaceutical and environmental areas. In terms of the synthesis and characterization of the Ni(Salpn) complex, it was possible to confirm by means of techniques of material characterization the efficiency of the methods used. Analogously, the electropolymerization was performed successfully, obtaining nano-films with a thickness of approximately 110 nm with excellent electrochemical activity. The evaluation in the application of the poly[Ni(Salpn)] nano-metallopolymer showed an excellent response against H2O2, having a fast response, a linear range of 4.99 x 10-5 to 1.48 x 10-3 mol L-1, with detection limit of 7.68 x 10-6 mol L-1 and sensitivity of 24,05 μmol mmol-1, thus making possible the construction of a viable, fast, precise and accurate sensorial platform for the purpose of resolution of analytical problems.
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Low, May Lee. "Synthèse, caractérisation et bioactivité de ligands issus de bases de Schiff dérivées de dithiocarbazate et de leurs complexes métalliques." Thesis, Paris 6, 2014. http://www.theses.fr/2014PA066148/document.
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Il y a de nos jours un besoin urgent de découvrir de nouveaux médicaments pour relever le défi de la multirésistance dans le traitement des infections bactériennes et le cancer. Dans cette perspective, des bases de Schiff dérivées de dithiocarbazates et leurs complexes métalliques correspondants sont des candidats intéressants puisqu'ils peuvent être facilement synthétisés et permettent une grande diversité de coordination. Dans cette étude, des complexes tetradentes et bidente ont été préparés. Les ligands et complexes synthétisés ont été entièrement caractérisés par différentes méthodes spectroscopiques et physico-chimiques dans le solide et en solution. L'activité antibactérienne de ces complexes a ensuite été étudiée et a permis de sélectionner un complexe " leader " (plus efficace, stable et fonctionnalisable). Ce complexe a alors été modifié afin d'augmenter sa stabilité en milieux biologique, sa solubilité dans l'eau ainsi que son activité. Il a été conjugué avec différentes entités : des peptides pénétrants, un polyéthylène glycol (PEG) et un peptide inhibiteur des pompes d'efflux bactériennes. Ces complexes ont montré une remarquable activité antibactérienne sur neuf souches de bactéries Gram-positives et Gram-négatives et en particulier, ils se sont avérés très efficaces contre S.aureus. L'activité anti-cancéreuse des complexes non-conjugués a également été étudiée et les complexes de cuivre sélectionnés et testés sur des cellules de cancer du sein ont montré une cytotoxicité élevée. Ceci met en évidence la pertinence d'utiliser les complexes métalliques, pour à la fois stabiliser les ligands et générer des composés plus actifsThere is an urgent need to discover new drugs with novel mechanisms of action, higher activity and improved selectivity to address the severe challenge of multidrug resistance in treating bacterial infections and cancer. In view of this, Schiff bases derived from S-substituted dithiocarbazate and their corresponding metal complexes with a plethora of potentially exciting biological activities and coordination chemistry are attractive candidates. Metal complexes of tetradentate NNSS and bidentate NS ligands have been prepared. The compounds were fully characterized with various physico-chemical and spectroscopic methods in solution and solid state. Conjugation of the most promising antimicrobial compound to various moities (polyarginine, polyethylene glycol (PEG) and an bacterial efflux pump inhibitor) was achieved to prepare improved therapeutic agents. The nanoarginines (R9) derivatives showed the most encouraging synergistic effect upon conjugation and complexation to copper ion with enhanced water solubility, bacteria cell membrane permeability and bioactivity. The Cu(II) R9 derivatives possess remarkable antibacterial activity against a wide spectrum of bacteria and in particular, highly efficacious against S. aureus. This show that the conjugation of polyarginine to dithiocarbazate compounds can greatly influence their therapeutic potential. Cytotoxic assay was also carried out for selected non-conjugated compounds. All the selected Cu(II) complexes assayed against breast cancer cells lines exhibited good cytotoxicity. This work highlights the relevance of the strategy that consists of using metal complexes to stabilize the ligands and improve their bioactivity
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Bosque, Pueyo Ramón. "Preparación y ciclopaladación de bases de Schiff derivadas del ferroceno." Doctoral thesis, Universitat de Barcelona, 1994. http://hdl.handle.net/10803/2782.
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Una de las áreas de la Química Organometálica que ha suscitado mayor interés en los últimos 25 años es el estudio de los procesos de activación de enlaces C-H, mediante compuestos de elementos de transición. Dentro de este contexto los procesos conocidos como reacciones de ciclometalación son unos de los más ampliamente estudiados, y en particular aquellos en los que se utilizan sales de paladio (II) y sustratos orgánicos que poseen nitrógeno como heteroátomo. El mecanismo que se propone en este caso concreto consiste en dos etapas sucesivas: a) la coordinación del heteroátomo y b) un ataque electrofilo de la especie formada al enlace C-H.Por otra parte, si bien en la bibliografía se han descrito un gran número de reacciones de ciclopaladación de ligandos N-dadores derivados del benceno, los estudios que versan sobre substratos análogos con grupos ferrocenilo son sumamente escasos, a pesar de ser bien conocido que el ferroceno es mucho más proclive a experimentar reacciones del substitución electrofila. En consecuencia, parecía interesante llevar a cabo un trabajo paralelo basado en el estudio de los procesos de ciclopaladación de ferroceniliminas y ferrocenilazinas que permitiese obtener compuestos con Sigma(Pd-C/sp(2), ferroceno), que presentan el interés adicional de la quiralidad inherente a los derivados 1,2- disubstituidos del ferroceno.
El trabajo que se resume en esta Memoria está enmarcado dentro de este campo y tiene como objetivo fundamental abordar el estudio de los procesos de ciclopaladación de bases de Schiff con grupos ferrocenilo que permita:
a) comparar la facilidad de activación de los enlaces Sigma(C(sp)2, (ferroceno)-H) frente a los Sigma(C(sp)2, (fenilo)-H) e incluso Sigma(C(sp)3, (alifático)-H),
b) evaluar la importancia del llamado "efecto endo",
c) establecer la influencia del tamaño del paladociclo (y en particular, el número de átomos que lo constituyen) sobre la estabilidad de estos compuestos,
d) determinar la importancia del carácter básico del átomo de nitrógeno coordinado al paladio sobre la estabilidad y reactividad del enlace O'(Pd-N),
e) estimar la influencia de los efectos estéricos en estos procesos de activación de enlaces carbono-hidrógeno,
f) apreciar la incidencia de la posible formación de dos ciclos fusionados de cinco miembros, [5, 5] - el propio metalociclo y el anillo ciclopentadienilo - en el proceso de ciclometalación.
Con estas premisas iniciales, el trabajo que se resume en esta Memoria se ha dividido en dos partes marcadamente diferenciadas:
a) Preparación y caracterización de bases de Schiff mono- y difuncionales derivadas del ferroceno y,
b) Estudio de los procesos de ciclopaladación de derivados del ferroceno con el grupo funcional >C=N- del tipo iminas y azinas.
This Thesis deals with the synthesis and characterization of ferrocene derivatives containing the functional group >C=N-, and with the study of their cyclopalladation reactions. The work is divided in two parts:
a) Preparation and characterization of novel Schiff bases of general formulae.
b) The study of the cyclopalladation reactions of these derivatives as well as those of ferrocenylazines, which have aIlowed to isolate and characterize palladium (II) compounds with different sorts of Pd-C bonds (C(sp)(2) phenyl, C(sp)(2) ferrocene or C(sp)(3).
All the compounds have been characterized by elemental analyses, infrared spectroscopy, nuclear magnetic resonance, Mossbauer spectroscopy and electrochemical studies -based on cyclic voltammetries- on these compounds are also included and have allowed to elucidate the influence of the substituents -including the palladium (II)- on the Fe(II) environment.
The X-ray crystal structures of three imines of general formulae and four palladium compounds have been solved and refined.
Finally, the work summarized in this Thesis has also allowed to elucidate the relative importance of several factors, such as the "endo" effect, the different proclivity of benzene and ferrocene derivatives to undergo electrophilic substitution, and the size and structure of the metallacycle upon the nature of the final Pd (11) compound formed through activation of the Sgyma(C-H) bonds.
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Anselmo, Daniele. "Lewis acidic zn(ii) schiff base complexes in homogeneous catalysis." Doctoral thesis, Universitat Rovira i Virgili, 2013. http://hdl.handle.net/10803/127634.
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El trabajo descrito en esta tesis muestra estudios hacia nuevas aplicaciones de complejos derivados de bases de Schiff en catálisis homogénea. En concreto, se han investigadoligandos “salen” (incluyendo sistemas quelantes N2S2) ytambiénse han examinado otros aspectos que generalmente se consideran importantes en el contexto del aumento de la sostenibilidad de los procesos químicos. Estudios sobre el uso de estos compuestos acidos de Lewis en la catálisis de la fijación de dióxido de carbono, de reacciones de múltiples componentespara obtener indoles sustituidos y de reciclado de agregados supramoleculares basados en triptyceno han revelado un ancho potencial de aplicación. Los complejos Zn(salen) se han evaluadotambién como "espectadores" en la construcción de ligandos supramoleculares basados en fosfinas voluminosas que demostraron ser útiles en la catálisis de hidrosililación. Por lo tanto, el trabajo descrito en esta tesis puede servir como un punto de partida para el desarrollo de un nuevo potencial catalítico para los complejos de bases de Schiff.The work described in this thesis shows studies towards new applications of Schiff base complexes in homogeneous catalysis . Specifically, we investigated “salen” ligands (including N2S2 chelating systems) and also examined other aspects that are generally considered important in the context of increasing the sustainability of chemical processes. Studies on the use of these Lewis acidic compounds in the catalysis of the fixation of carbon dioxide, multicomponent reactions for the synthesis of substituted indoles and the recycling of triptycene based supramolecular aggregates revealed a wide potential of application. The Zn(salen) compexeswere evaluated as "spectators" in the construction of supramolecular ligands based on bulky phosphines which proved to be useful in hydrosilylation catalysis. Therefore, the work described in this thesis may serve as a starting point for the development of a new catalytic potential of Schiff base complexes.
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Weingart, Oliver. "Ab-initio-Moleküldynamik der Photoisomerisierung von protonierten Polyenaldehyd Schiff Basen." [S.l. : s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=975608878.
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Kim, Shang U. "SYNTHETIC EFFORTS TOWARD FUMONISIN via AMINO ACID SCHIFF BASE METHODOLOGY." Diss., The University of Arizona, 2009. http://hdl.handle.net/10150/193674.
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Synthetic efforts toward fumonisin analog were described. These are accomplished via amino acid Schiff base methodology. These efforts can be divided three major phases. First, tandem reductive alkylation with DIBAL/TRIBAL and different types of organo-lithium or Grignard nucleophiles provided threo-amino alcohol with excellent stereoselecitivites (2-27:1). The reductive alkylation utilized most hydrocarbon nucleophiles, e.g. alkyl-, vinyl-, alkenyl-, phenyl-, and dienyl-, and afforded high selectivites unless donor solvents (e.g. THF and Et2O) were used. Second, syntheses of the protected threo-γ-amino-β-hydroxy aldehydes and their stereoselectivities were introduced. The reductive alkylated threo-amino allyl alcohol was transformed via Brown’s hydroboration/oxidation protocol with 9-BBN, followed by TEMPO oxidation to give the resultant aldehydes in reasonable yields. Then, TBDPS and Schiff base protected aldehyde was coupled with phenyl- and decyl Grignard reagents to obtain predominant 3,5-anti-diols (ca. 80:20 anti:syn), characterized by ¹³C NMR analysis of Rychnovsky’s 1,3-acetonide groups. Products can be useful analogues for fumonisin and 5-hydroxy-sphingosine due to their structural similarity. Third stage involved the synthesis of C₁₁-C₂₀ fragment analog of fumonisin. Chiral auxiliaries (e.g. Evans and Myers) were administrated for stereoselective methylation, Sharpless asymmetric dihydroxylation in the presence of (DHQ)2PHAL catalyst was performed to form 1,2- syn-diols, and the manipulation of protection/deprotection and Finklestein reaction furnished C₁₁-C₂₀ fragment analog of fumonisin.
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Santos, Juliana Alves dos. "Preparação e avaliação biológica de conjugados esteroides/bases de Schiff." Universidade Federal de Juiz de Fora (UFJF), 2015. https://repositorio.ufjf.br/jspui/handle/ufjf/7225.
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CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
A presente tese, intitulada "Preparação e avaliação biológica de conjugados esteroides/bases de Schiff" trata, sobretudo, da preparação, caracterização e avaliação do potencial biológico de compostos orgânicos contendo uma porção esteroidal associada a uma base de Schiff nos quais a conjugação se deu nas posições C-3 ou C-24 dos núcleos esteroidais cólico, desoxicólico ou colesterol. Além destes, encontra-se descrita também a preparação de derivados destas duas classes de compostos de forma não conjugada. Os compostos aqui descritos foram preparados através da utilização de metodologias clássicas em síntese orgânica, as quais envolvem a formação de amidas, reações de esterificação e formação de iminas; todas relacionadas à química de compostos carbonílicos. As estruturas químicas dos produtos obtidos, bem como as dos intermediários sintéticos, foram devidamente confirmadas por espectroscopia no infravermelho, de ressonância magnética nuclear de próton e de carbono, por espectrometria de massas, além de faixa de fusão e análise elementar. Os compostos sintetizados foram avaliados como potenciais antiparasitários (leishmanicidas e antimaláricos), antibacterianos (antituberculosos) e antioxidantes (inibidores do radical DPPH). Tais propriedades foram selecionadas por já serem atividades descritas para as duas classes de moléculas exploradas neste trabalho- derivados esteroidais e bases de Schiff. Baseado nas estruturas dos compostos descritos neste trabalho realizou-se também testes de avaliação da atividade fotoprotetora (fatores de proteção solar UVA e UVB e determinação do comprimento de onda crítico) de alguns dos conjugados obtidos. Grande parte dos compostos sintéticos apresentaram atividade biológica promissora.
The thesis entitled ―Preparation and biological evaluation of conjugated steroids/Schiff bases‖ deals mainly with the preparation, characterization and evaluation of the biological potential of organic compounds containing a steroid portion associated with a Schiff base in which the conjugation occurred the C-3 or C-24 positions of the steroid nucleus cholic, deoxycholic or cholesterol. In addition, is also described the preparation of derivatives of these two classes of compounds in non conjugated form. The compounds described herein were prepared by using classical methods of organic synthesis, which involves amide formation, sterification and imine formation; all related to chemistry of carbonyl compounds. The chemical structures of the obtained products, as well as synthetic intermediates were confirmed by infrared spectroscopy, nuclear magnetic resonance of proton and carbon, by mass spectrometry, elemental analysis and melting point. The synthesized compounds were evaluated as potential antiparasitic (antileishmanial and antimalarial), antibacterial (antituberculosis) and antioxidants (DPPH radical inhibitors). These properties have been selected by already being activities described for the two classes of molecules explored in this work-steroidal derivatives and bases Schiff. Based on the structures of the compounds described in this work also conducted evaluation tests of sunscreen activity (sun protection factor UVA and UVB, and determining the critical wavelength) of some of the conjugates. Much of the synthetic compounds showed promising biological activity.
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Xiang, Tengfei. "Synthesis and Characterization of Polymeric Schiff Bases from 2,5-Diformylfuran." University of Akron / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=akron1353710697.
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Marrs, Deborah Jane. "Macrocycles, macrobicycles : a study." Thesis, Open University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.257447.
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Lo, Wing Kit. "Synthesis, characterization and luminescent properties of mono- and bi-metallic Schiff base complexes." HKBU Institutional Repository, 2004. http://repository.hkbu.edu.hk/etd_ra/585.
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Sobola, Abdullahi Owolabi. "Synthesis, characterization and antimicrobial activity of copper (II) complexes of some hydroxybenzaldimines and their derivatives." Thesis, Rhodes University, 2012. http://hdl.handle.net/10962/d1016258.
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This study focuses on the antimicrobial activity of Cu(II) complexes of some orthohydroxybenzaldimines and its derivatives. Four different categories of Schiff base ligands were prepared by condensing salicylaldehyde, o-vanillin, p-vanillin and vanillin with p- and osubstituted anilines; 1-aminonaphthalene; 2- and 3-aminopyridine; 2- and 3- aminomethylpyridine as well as 2-aminobenzimidazole. The last category was prepared from ophenylenediamine and o-vanillin. The Schiff base ligands have been characterized by a combination of elemental analysis and spectral (¹H- and ¹³C-NMR, UV/Visible, infrared and Raman) data. The existence of strong intramolecular hydrogen bonding in the orthohydoxybenzaldimines was evident from the chemical shift values of the hydroxyl proton in the ¹H-NMR spectra of the Schiff base ligands. The hydroxyl proton resonates at high frequency and thus absorbed far downfield at 13.46-11.83 ppm, reflecting the presence of hydrogen bonding between the hydroxyl proton and the imine nitrogen. In the p-substituted aniline analogues of the Schiff base, a plot of the chemical shift values of the hydroxyl proton against the Hammett's substituent parameters gave a linear correlation between the electronegativities of the substituents and the chemical shift values. The nitro group with the highest electronegativity caused the least deshielding of the hydroxyl proton and thus absorbed upfield compared to the less electronegative substituents such as the CH3 and OCH3 analogues. Likewise, in the solid state infrared spectra of the ligands, the hydroxyl stretching band of the ortho-hydroxyl Schiff base ligands was observed as a very broad band and at much lower frequency, 3100-2100 cm⁻¹, indicating the existence of strong intramolecular hydrogen bonding. In the same vein, ¹H- and ¹³C-NMR spectral data for the Schiff base ligands indicated that the prepared compounds exist in the enol form in aprotic solvent, chloroform. The methine proton appeared as singlet and there was no carbonyl signal in the ¹³C-NMR spectra of the Schiff base ligands. This was supported by the infrared data having no vibrational band attributable to the carbonyl stretching of the keto-form of the Schiff base ligands in solid state. However, the UV/Visible study of the Schiff base ligands in protic solvent, methanol, suggested the existence of some of the Schiff base ligands in keto-enol form. A band at greater than 400 nm was observed in the UV/Visible spectra of the ligands and this has been attributed to the presence of the keto form of orthohydroxyl Schiff base ligands in solution. A plot of the molar absorptivity (ε) of the band at greater than 400 nm against Hammett substituent parameters revealed that the intensity of the bands increased with the electronegativity of the substituents. The Cu(II) complexes of salicylaldehyde, o-vanillin and a few p-vanillin based Schiff base ligands are reported in this work. It was observed that introduction of Cu(II) ions into the ligand system resulted in the hydrolysis of the imine band in few cases. All the isolated complexes have been characterized by elemental analysis, conductivity measurement, infrared and UV/Visible spectral data. The structures of three of the Cu(II) complexes were further confirmed by X-ray single crystal diffraction. The Schiff base ligands either coordinated as neutral base through the imine nitrogen or via the imine nitrogen and the phenolic oxygen atoms. In addition, the benzimidazole-based and ovan-2-pico analogues equally coordinated through the imidazole N-3 nitrogen and the azine nitrogen respectively; thus acted as tridentate. In general, the synthesized Cu(II) complexes fell into seven categories viz: [Cu(LH)Cl(H₂O)]Cl; [Cu(LH)₂Cl₂].xH₂O; [CuL₂]; [Cu₂L₂]; [Cu(LH)Cl(H₂O)]Cl; and [MLCl]. The Cu(II) complexes of the form, M(LH)₂Cl₂.xH₂O were either 1:1 or non-electrolyte in methanol and DMF. The third category, CuL₂, was however, non-electrolyte existing as neutral four coordinate Cu(II) complexes. X-ray single crystal structure of Cu(II) complexes derived from the ammonia-based Schiff bases revealed a square planar geometry for the complexes and this agreed with the planar geometry that has been reported for Cu(II) complexes of N-arylsalicylaldimines of the type studied in this work. The complexes, [Cu₂L₂], resulted from the ortho-hydroxyaniline analogues and were polymeric with the Schiff base ligands coordinating to the Cu(II) ions as tridentate dibasic via the imine nitrogen, phenolic oxygen and the aminophenolic oxygen atoms. Cu(II) complexes prepared from ovan-2-ampy and ovan-2-pico Schiff bases were of the forms [Cu(LH)Cl(H₂O)]Cl and [CuLCl] respectively. The X-ray crystal structure of [Cu(ovan-2- pico)Cl] revealed a four-coordinate square planar geometry for the complex. In the same vein, the o-phenylenediamine complexes were of the form [Cu(L)(H₂O)], with the X-ray crystal structure of [Cu(bis-ovanphen)(H₂O)] revealing a square pyramidal geometry. The Schiff base ligands and the isolated Cu(II) complexes have been evaluated for their antimicrobial activity against three bacterial strains (Escherichia coli ATCC® 8739™*, Staphylococcus aureus subsp. aureus ATCC® 6538™* and Bacillus subtilis subsp. spizizeni ATCC® 6633™*) and one fungal strain, Candida albicans ATCC® 2091™*, using agar disc diffusion and broth dilution techniques. It was observed that the presence of the methoxyl group at the ortho-position of the aldehyde moiety of the Schiff base ligands enhanced the activity of the ligand tremendously and thus the o-vanillin analogues showed the highest potency against the tested organisms. In addition, the hydroxyaniline analogues were equally the most promising of all the substituted aniline based Schiff bases. The o-vanillin analogues of the aminopyridines and aminomethylpyridines also exhibited significant activity against the tested organisms. All the 2-aminobenzimidazole series were active against the tested organisms. It should be noted that E. coli was the least susceptible of all the microorganisms while the highest potency was exhibited against the fungus of choice, Candida albicans. Lastly, chelation of the Schiff base ligands with Cu(II) ions did not have significant influence on the activity of the free ligands.
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Liu, Xiang. "Nanomatériaux à base d'éléments de transition tardifs pour la catalyse de réactions "click" et impliquant des liaisons carbone-azote." Thesis, Rennes 1, 2017. http://www.theses.fr/2017REN1S113/document.
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La conception et la synthèse de nanomatériaux à base d'éléments de transition tardifs est d’un intérêt considérable pour des applications potentielles respectueuses de l’environnement en nanomédecine, pour la reconnaissance moléculaire, dans le domaine des capteurs, et en catalyse. Onze différents types de nanoparticules de métaux de transition (TMNPs) stabilisées par des dendrimères ont été synthétisées et caractérisées. Ces nanomatériaux ont été employés en tant que catalyseurs dans des réactions ''click'' et de réduction du nitrophénol en aminophénol dans le but d’établir une relation entre leurs activités catalytiques et la localisation de la nanoparticule qui peut être totalement ou partiellement encapsulée par le dendrimère. Par ailleurs, un complexe moléculaire base de Schiff organométallique de Cu(II) et le métallopolymère correspondant résultant de son greffage sur une matrice PMMA ont été préparés et utilisés comme précatalyseurs efficaces de réactions de cycloaddition [3+2] d’azotures organiques avec des alcynes terminaux. De plus, le dérivé supporté a été recyclé au moins trois fois sans perte d’activité ni de cuivre. Une réaction sélective de N-alkylation d’amines par des alcools en utilisant Pd/C comme catalyseur recyclable a également été développéeThe design and synthesis of late transition-metal nanomaterials is of considerable interest towards applications in nanomedicine, molecular recognition, sensing and catalysis under environmentally friendly conditions. Eleven different kinds of dendrimer-stabilized TMNPs have been synthesized and characterized. They were employed as catalysts for “click” and 4-nitrophenol reduction reactions, to study the relationship between their catalytic activities and their ''inside vs. partly outside'' dendrimer localization. On the other hand, a new ferrocenyl-containing unsymmetrical CuII-Schiff-base complex, and its covalently poly(methyl) (methacrylate) (PMMA)-grafted counterpart were synthesized and employed as efficient precatalyst in the CuAAC “click reaction. The PMMA-supported catalyst has been reused at least three times without any lost of activity or copper leaching. A selective NAlkylation reaction of amines with alcohols using Pd/C as an efficient and reusable catalyst has also been developed
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Morale, Francesca. "Metallomesogens derived from Schiff-base chelates and related co-ordination chemistry." Thesis, University of Nottingham, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.269486.
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Hunter, Mary Josephine. "Encapsulated metal ions : mononuclear complexes of Schiff-base macrocycles and cryptands." Thesis, Open University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.277902.
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Ross, Andrew Thomas. "Lead, indium and tin complexes of Schiff bases derived from salicylaldehydes." Thesis, Loughborough University, 1998. https://dspace.lboro.ac.uk/2134/26886.
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A number of lead(II) complexes prepared from the reactions of various disalicylaldimines with lead(II) salts have been characterised spectroscopically, and in two cases have been analysed by X-ray diffraction. The reaction of N,N'-bis(salicylidene)ethane-1,2-diamine (H2salen) with Pb(ClO4)2·6H2O produced a novel complex [Pb3(salen)2][ClO4]2 in which the ligand bonds to the lead in two different modes. The interaction of N,N'-bis(3-methoxy-salicylidene)ethane-1,2-diamine with Pb(ClO4)2·6H2O yielded a mononuclear complex wherein the ligand bonds to the lead(II) atoms only through its phenolic oxygens.
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Tozzo, Érica. "\"Estudo experimental e teórico de compostos de bases de Schiff com cobre (II)\"." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/75/75132/tde-05062007-162938/.
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Neste trabalho inicialmente foi feita uma breve apresentação sobre a utilização de compostos de bases de Schiff e Cobre(II) como catalisadores na reação de oxidação de sulfetos. Foi feita a determinação das estruturas cristalinas dos compostos: N,N\'-bis(3-etoxisalicilideno)-(1,2etileno- diamina) Cu(II), sistema cristalino ortorrômbico grupo espacial Pbcn a = 7.639(5); b= 12.760(5); c= 19.733(5)Å; V = 1923.4(15) (3)Å3; Dcalc = 1.505 Mg/m3; MM = 435.96; e m = 1.170 mm-1, N,N\'-bis (4-dietilaminasalicilideno) - (1,2etilenodiamina) Cu(II), sistema monoclínico, C2/c, a = 19.571(2); b=9.8514(2)=; c=12.4552(4) Å; Beta = 93.705(9)o; V =2396.4(5) Å3; Dcalc=1.358 Mg.m-3; MM= 490.10; e m = 0.944 mm-1, N,N\'-bis(3-metoxisalicilideno)-(1,2etilenodiamina)Cu(II), sistema ortorrômbico, Pna21, a = 7.5140(6); b= 9.2629(9); c= 24.721(3)Å; V =1720.6(3) Å3; Dcalc = 1.575 Mg,m-1; MM = 407.91; e m = 1.302 mm1 e (SALAHE)Cu(II), monoclínico, P21/C, a = 18.3216(2) Å; b=4.804(3) Å; c=19.801(2)Å; Beta = 98.908(6)o; V =2396.4(5) Å3; Dcalc=1.358 Mg.m-3; MM= 490.10; e m = 0.944 mm-1. Os cálculos teóricos para as quatro moléculas foram efetuados partindo-se das coordenadas atômicas cristalográficas. Foram modeladas, para posterior estudo teórico, as moléculas de vinte e seis compostos de bases de Schiff e Cobre(II) análogos. Foram calculadas 104 variáveis para cada composto, e realizado o estudo de correlação estrutura-atividade catalítica através de métodos de Quimiometria. Foi obtido um modelo de correlação utilizando a classe de compostos de atividade catalítica pré-definida. Finalmente foi realizada a tentativa de previsão de atividade dos vinte e quatro compostos com atividade não conhecida, obtendo-se como resultado a probabilidade de vinte deles serem ativos como catalisadores da conversão sulfeto-sulfóxido .Initially, in this work, a brief presentation about Schiff bases and their applications as catalysist. The crystalline structure determination was made for the compounds: N,N\'-bis(3-etoxysalicylidene)- (1,2ethylenediamine) Cu(II), crystal system orthorhombic spatial group Pbcn a = 7.639(5); b= 12.760(5); c= 19.733(5)Å; V = 1923.4(15) (3)Å3; Dcalc = 1.505 Mg/m3; MM = 435.96; e m = 1.170 mm-1, N,N\'-bis (4- diethylaminesalicilidene) - (1,2ethylenediamine) Cu(II), monoclinic, C2/c, a = 19.571(2); b=9.8514(2)=; c=12.4552(4) Å; B= 93.705(9)o; V =2396.4(5) Å3; Dcalc=1.358 Mg.m-3; MM= 490.10; e m = 0.944 mm-1, N,N\'-bis(3-metoxysalicilidene)- (1,2ethylenediamine) Cu(II), orthorhombic, Pna21, a = 7.5140(6); b= 9.2629(9); c= 24.721(3)Å; V =1720.6(3) Å3; Dcalc = 1.575 Mg,m-1; MM = 407.91; e m = 1.302 mm1 e (SALAHE)Cu(II), monoclinic, P21/C, a = 18.3216(2) Å; b=4.804(3) Å; c=19.801(2)Å; B= 98.908(6)o; V =2396.4(5) Å3; Dcalc=1.358 Mg.m-3; MM= 490.10; e m = 0.944 mm-1. The theoretical calculations for the four molecules had been effected starting of the crystallographic atomic coordinates. Twenty-six molecules without determined crystallographic structure had been shaped for theoretical study. 104 variables for each compound had been calculated, and carried through the correlation study structure-catalyst activity through chemometric methods. A separation model was gotten in one single class. Finally the attempt of forecast of activity of twenty four compounds with activity unknown was carried through, getting itself as resulted the probability of twenty in all to be able to become active.
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Araújo, Eliene Leandro de. "Preparação e caracterização de bases de Schiff e complexos metálicos a partir de quitosana e derivados de salicilaldeído." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/75/75135/tde-29062015-154801/.
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Bases de Schiff biopoliméricas à base de quitosana foram preparadas a partir do salicilaldeído e de seus derivados substituídos na posição 5 do anel aromático do salicilaldeído (5-bromo, 5-cloro, 5-metil, 5-metóxi e 5-nitrosalicilaldeído), utilizando condições de síntese otimizadas para aumentar o grau de substituição (GS). Durante a caracterização das bases foram observados GS (%) = 78,7; 51,3; 43,7; 28,1; 22,1 e 17,5, respectivamente para os derivados 5-metóxi, salicilaldeído, 5-nitro, 5-cloro, 5-metil e 5-bromo, tendo sido as diferenças atribuídas ao caráter indutivo e de ressonância de cada um dos grupos substituintes. A partir desses ligantes foram sintetizados os complexos de cobre (II) e níquel (II) com quitosana e todas as bases de Schiff biopoliméricas. A quitosana, os ligantes e os complexos foram caracterizados por espectroscopia vibracional na região do infravermelho com transformada de Fourier (FTIR) e técnicas termoanalíticas (termogravimetria, TG; termogravimetria derivada, DTG e análise térmica diferencial, DTA). A quitosana utilizada apresentou grau de desacetilação, GD = 75,6%, determinado por 1H RMN, e apresentou as bandas características para estes biopolímeros nos espectros FTIR e decomposição térmica em dois eventos exotérmicos, após desidratação. As curvas TG/DTG-DTA das bases revelaram que estas são menos estáveis que a quitosana de partida e a estabilidade mostrou-se mais uma função da natureza do ligante do que do GS. A partir das curvas TG e dos valores de GS foi possível prever a composição das bases em concordância com os dados de análise elementar. Os complexos mostraram coordenação com os átomos de oxigênio do anel aromático dos aldeídos e do nitrogênio imínicos, com base nos espectros FTIR, sendo os complexos de cobre aparentemente mais fortes que os de níquel, se considerados os deslocamentos nas frequências de vibração das ligações C=N e C-Ofen. Os complexos de cobre (II) e níquel (II) também apresentaram decomposição em duas etapas, após desidratação, tendo sido a primeira etapa observada em temperaturas inferiores às das bases. Em alguns casos foi possível observar que os processos de decomposição se dividem, sugerindo decomposição diferenciada para regiões do biopolímero contendo o complexo e aquelas não modificadas, pois tal fenômeno ocorreu principalmente nos complexos derivados das bases com menor GS. Os resíduos de decomposição desses complexos foram CuO e NiO, de acordo com difratogramas de raios X, cujos teores permitiram calcular a quantidade de metal presente em cada complexo, e concluir que praticamente todos os sítios contendo as bases biopoliméricas foram complexadas em ambos os casos.Biopolymeric Schiff bases were prepared from chitosan and salicylaldehyde and its 5-bromo, 5-chloro, 5-methyl, 5-methoxy and 5-nitro derivatives, under conditions optimized to improve the degree of substitution (DS). From 1H NMR data, DS (%) = 78.7, 51.3, 43.7, 28.1, 22.1 and 17.5, for 5-methoxy, salicylaldehyde, 5-nitro, 5-chloro, 5-methyl, and 5-bromo derivatives, respectively. The differences had been attributed to inductive and resonance effects of each substituent. From these ligands, copper (II) and nickel (II) complexes were synthesized with chitosan and all the biopolymeric Schiff bases. Chitosan, ligands and complexes were characterized by Fourier transform vibrational spectroscopy in the infrared region (FTIR) and thermal analytical techniques (thermogravimetry, TGA; derivative thermogravimetry, DTG and differential thermal analysis, DTA). Chitosan presented a deacetylation degree, DD = 75.6%, determined by 1H NMR, presenting the characteristic bands of this biopolymer in the FTIR spectra as well as decomposition in two exothermic steps after dehydration. TGA/DTG and DTA curves of the bases revealed that they are less stable than chitosan. This stability is closely related to the nature of substituent than the DS. From TGA curves and DS values it was possible to calculate the bases composition which agreed with elemental analysis data. Complexes presented coordination via oxygen atom of aldehydes aromatic rings and the iminic nitrogen, based on the FTIR results, being the copper (II) complexes apparently stronger the those from nickel (II), if one consider the displacements in the vibration frequencies of the C=N and C-Ophen bonds. The copper (II) and nickel (II) complexes also presented decomposition in two steps after dehydration, being the first step observed in lower temperatures when compared to those of the free bases. In some cases it was possible to observe that the decomposition steps in the DTG curves are split suggesting different decomposition for regions of the biopolymer in which the complexes is present and for the unmodified ones, once such phenomena occurred mainly in complexes derived from the bases with lower DS. The residues of decomposition for such complexes were CuO and NiO, according to X-ray diffractograms and their contents permitted to calculate the amount of each metal present in the complex leading to conclude that almost all the sites containing the Schiff bases on the biopolymeric matrix was complexed in both cases.
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Afonso, Maria Beatriz Alves [UNESP]. "Complexos de rutênio(II) coordenados à Bases de Schiff derivadas de cicloalquilaminas como precursores catalíticos para ROMP de norborneno e ATRP de metacrilato de metila." Universidade Estadual Paulista (UNESP), 2017. http://hdl.handle.net/11449/150896.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
A investigação de sistemas catalíticos duais capazes de mediar as reações de polimerização por abertura de anel via metátese (ROMP) e de polimerização radicalar por transferência de átomo (ATRP) simultaneamente é de grande interesse e importância na obtenção de novos materiais com potencial de aplicação. Neste estudo, novos complexos de rutênio(II) coordenados a diferentes bases de Schiff derivadas de cicloalquilaminas (ciclopentil 1a, cicloexil 1b, cicloheptil 1c e ciclooctil 1d) foram sintetizados: [RuCl(CyPen-Salen)(PPh3)2] 2a, [RuCl(CyHex-Salen)(PPh3)2] 2b, [RuCl(CyHep-Salen)(PPh3)2] 2c e [RuCl(CyOct-Salen)(PPh3)2] 2d. As bases de Schiff e seus respectivos complexos de rutênio foram caracterizados por FTIR, UV-Vis, RMN e voltametria cíclica. Os complexos planejados foram avaliados como precursores catalíticos em reações de ROMP de norborneno (NBE) e em reações de ATRP de metacrilato de metila (MMA). As sínteses de polinorborneno (poliNBE) via ROMP com os complexos 2a-d como pré-catalisadores foram avaliadas sob diferentes condições de reação ([HCl]/[Ru], [EDA]/[Ru], [NBE]/[Ru] e temperatura). Os melhores rendimentos de poliNBE foram obtidos a 50 °C com razão molar [NBE]/[HCl]/[Ru] = 5000/25/1 na presença de 5 µL de EDA por 60 minutos. A polimerização de MMA via ATRP foi conduzida usando os complexos 2a-d na presença de etil-α-bromoisobutirato (EBiB) como iniciador. Os testes catalíticos foram avaliados em função do tempo de reação usando a razão molar [MMA]/[EBiB]/[Ru] = 1000/2/1. Todos os experimentos via ATRP foram conduzidos à 85 °C. A correlação linear do ln([MMA]0/[MMA]) em função do tempo na ATRP de MMA mediada pelos complexos 2a-d indica que a concentração de radicais permanece constante durante a polimerização. As massas moleculares aumentaram linearmente com a conversão com a diminuição dos valores de IPD, no entanto, as massas moleculares experimentais foram maiores do que as massas moleculares teóricas.
The investigation of dual catalytic systems able to mediate simultaneously ring-opening metathesis polymerization (ROMP) and atom-transfer radical polymerization (ATRP) reactions is of great interest and importance in obtaining new materials with potential for application. In the study, ruthenium(II) complexes of Schiff base derived from cycloalkylamines (cycloalkyl = cyclopentyl 1a, cyclohexyl 1b, cycloheptyl 1c and cyclooctyl) 1d were synthesized: [RuCl(CyPen-Salen)(PPh3)2] 2a, [RuCl(CyHex-Salen)(PPh3)2] 2b, [RuCl(CyHep-Salen)(PPh3)2] 2c and [RuCl(CyOct-Salen)(PPh3)2] 2d. The Schiff bases 1a-d and their respective RuII complexes 2a-d were characterized by FTIR, UV-Vis, NMR, and cyclic voltammetry. The complexes 2a-d were evaluated as catalytic precursors for ROMP of norbornene (NBE) and for ATRP of methyl methacrylate (MMA). The syntheses of polynorbornene (polyNBE) via ROMP with complexes 2a-d as pre-catalysts were evaluated under different reaction conditions ([HCl]/[Ru], [EDA]/[Ru], [NBE]/[Ru], and temperature). The highest yields of polyNBE were obtained with [NBE]/[HCl]/[Ru] = 5000/25/1 molar ratio in the presence of 5 µL of EDA for 60 minutes at 50 °C. MMA polymerization via ATRP was conducted using the complexes 2a-d in the presence of ethyl-α-bromoisobutyrate (EBiB) as initiator. The catalytic tests were evaluated as a function of the reaction time using the initial molar ratio of [MMA]/[EBiB]/[Ru] = 1000/2/1 at 85 °C. The linear correlation of ln([MMA]0/[MMA]) and time clearly indicates that the concentration of radicals remains constant during the polymerization and that the ATRP of MMA mediated by 2a-d proceeds in a controlled manner. Molecular weights increased linearly with conversion, however, the experimental molecular weights were higher than the theoretical ones.
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Conner, Elaine Margaret. "Novel metal conjugates as potential anti colitic agents." Thesis, University of Strathclyde, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.249764.
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Benny, Paul. "Synthesis and characterization of Rhenium (III & V) Schiff base complexes for nuclear medicine /." free to MU campus, to others for purchase, 2001. http://wwwlib.umi.com/cr/mo/fullcit?p3025602.
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