Dissertations / Theses: 'Synthesis of iron acyl'

1

Bromley, L. A. "Iron acyl complexes in synthesis." Thesis, University of Oxford, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.237924.

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2

Preston, Simon Christopher. "Asymmetric synthesis via iron acyl complexes." Thesis, University of Oxford, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.236153.

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3

Fraser-Bell, G. "Asymmetric synthesis via iron acyl compounds." Thesis, University of Oxford, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329923.

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4

Easton, R. J. C. "Stereoselective synthesis via iron acyl complexes." Thesis, University of Oxford, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.379991.

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5

Ayscough, A. P. "Stereoselective synthesis using iron acyl complexes." Thesis, University of Oxford, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234993.

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6

Walker, Jonathan Charles. "Asymmetric synthesis via iron acyl complexes." Thesis, University of Oxford, 1986. http://ora.ox.ac.uk/objects/uuid:55cfc478-5868-474f-9d2b-532218ec6fd6.

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7

Wills, M. "Synthetic application of iron acyl complexes." Thesis, University of Oxford, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.235128.

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8

Obuchowska, Agnes K. "Acyl transfer in chemical synthesis of oligosaccharides." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ34056.pdf.

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9

Warner, P. "Asymmetric synthesis via transition metal acyl complexes." Thesis, University of Oxford, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.355823.

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10

Simonian, Houri. "Acyl radical mediated polyene cyclisations in synthesis." Thesis, University of Nottingham, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.307815.

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11

Pepper, Adrian Gordon. "Asymmetric synthesis using acyl-nitroso cycloadditions : applications to natural product synthesis." Thesis, University of Salford, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.314011.

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12

Double, Philip John. "Acyl radical cascade reactions : the synthesis of azasteroids." Thesis, University of Nottingham, 1998. http://eprints.nottingham.ac.uk/27769/.

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Our work has been concerned with the synthesis of azasteroid ring systems, utilising acyl radical cascade reactions. Chapter 1 comprises an overview of published work relevant to our studies: an analysis of steroid biosynthesis and synthesis; a review of the use of azasteroids, their biological activity and current synthetic techniques in azasteroid formation. This initial chapter also includes an introduction to published work in the area of nitrogen heterocycle synthesis using radical reactions and finally the use of acyl radicals in synthesis, particularly cascade reactions. Chapter 2 starts by describing the requirements of a reaction system for use in acyl radical cascades and then discusses the relevance of this to the synthesis of ring junction azasteroids. Our attempts to synthesise ring junction azasteroids and the problems that we encountered are then discussed. Subsequent sections describe the disconnection of azasteroids where nitrogen is part of the body of the ring and the synthetic work that we performed in this area. Using cyclohexenyl enamides as the terminal electrophore in cascade reactions we were able to synthesise a 12-aza-D-homosteroid in nine steps. The final step was a cascade reaction involving three consecutive 6-endo-trig cyclisations starting from an acyl radical and terminating on an cyclohexenyl enamide electrophore. An extensive, though unsuccessful, study attempting to use linear enamides in cascade reactions is described showing routes towards the synthesis of steroid models. Finally we reveal the work that was performed in the use of highly stabilised enamides as radical acceptors. This work resulted in the formation of a bicyclo[8.3.0]tridecene after a 10-endo-trig, 5-exo-trig cascade from a linear precursor designed to form a 7-azaandrostane skeleton.

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13

Copeland, Christopher N. II. "Modified Conditions for Acyl Azide and Carbamate Synthesis." Youngstown State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1473765784542178.

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14

Dengiz, Cagatay. "Acyl Azides: Application To The Synthesis Of Various Heterocycles." Master's thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613892/index.pdf.

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Pyrazoles, isoindolinones, benzodizepinones and dihydroquinolinones are very important heterocycles for their biological properties. Many pharmaceutical agents include these units as core structures. Reactive molecules such as acyl azides, free radicals and formyl groups are used as key step reactants in these studies. Regiospesific hydrolysis and esterifications are used to reach target starting materials. Two different methodology are used for critical ring closure steps. Benzodiazepinones, and isoindolinones are obtained by base mediated ring closure reactions whereas thionyl chloride mediated procedure is used for dihydroquinolinones. Moreover, chloroacetonylation of the double bonds is also examined. Addition of acetylacetone to various alkenes was performed with in the presence of Mn(OAc)3 and HCl. Removal of one of the acetyl groups with ammonia under very mild conditions provided compounds derived from chloroacetonylation of the double bonds.

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15

Walters, Stephen John. "Acyl(oxy) carbene and vinylidene chemistry of iron and ruthenium half-sandwich complexes." Thesis, University of Sheffield, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245691.

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16

Sagandira, Cloudius Ray. "Exploring acyl azides chemistry in continuous flow systems." Thesis, Nelson Mandela Metropolitan University, 2017. http://hdl.handle.net/10948/12065.

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Organic azides are important in the synthesis of many target molecules of great use in fine chemical and pharmaceutical production. The use of this class of compounds is however limited due to their hazardous nature and many safety concerns, as they are highly exothermic. Micro reactors can handle exotherms extremely well, due to the inherent high surface area to volume ratio, unlike the conventional batch process. This dissertation therefore aims to investigate the safe application of micro reactors in acyl azide chemistry.With this in mind, Chapter 1 provides a comprehensive background on organic azides, reaction calorimetric studies, flow chemistry technology (micro reactors) and their theoretical advantages. This chapter also discusses the preparation of organic azides in continuous flow systems and scaling up in continuous flow systems. Chapter 2 illustrates and discusses multivariate optimisation of benzoyl azide synthesis as a model reaction, synthesis of other acyl azides using the model reaction optimised conditions and multistep synthesis of carbamates, amides and amines in continuous flow systems via the Curtius rearrangement of benzoyl azide formed in situ from benzoyl chloride and sodium azide. The chapter also discusses process hazards analysis and evaluation of benzoyl azide synthesis and decomposition using calorimetric studies. It also investigates and discusses the effects of different mixing regimes and channel sizes on scale up. Chapter 3 has comprehensive experimental details for the whole dissertation with Chapter 4 providing the concluding remarks and future work recommendations.

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17

Wells, Greggory M. "Synthesis and Biological Activity of N-Acyl Aziridines." Ohio University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1450458169.

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18

Chen, Ligong. "Polyene cyclisations initiated by acyl radicals leading to polycycle constructions." Thesis, University of Nottingham, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.240260.

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19

Vanderhoeven, Stephen John. "Synthesis and NMR studies on the reactivity of O-acyl glucuronides." Thesis, Imperial College London, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.400661.

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20

Perrie, Jennifer Anne. "New methods for the synthesis of O-alkyl and acyl glucuronides." Thesis, University of Liverpool, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.428259.

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21

Markey, Michael D. "Synthesis of cribrostatin 6, santiagonamine, and a N-acyl pyridinium salt." Thesis, Boston College, 2008. http://hdl.handle.net/2345/1358.

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22

Baris, Sehriban. "Synthesis And Reactions Of Alpha-keto-beta-hydroxyphosphonates." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/3/12608215/index.pdf.

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This thesis presents synthesis and different reactions of alpha-keto-beta-hydroxyphosphonates. Toward this aim, the hydroxyl functionality of alpha-hydroxycarboxylic acids were protected with alkyl or acyl groups and then formation of acid chloride followed by the reaction with trialkylphosphite furnished protected alpha-keto-beta-hydroxyphosponates. Nucleophilic addition reactions were applied to these compounds to obtain quaternary alcohols with phosphonate functionality. The addition reactions were tried with organocatalysts for the enantioselective formation of desired products.

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23

Reis, Barbaros. "Addition Of Acyl Phosphonates To Ethylcyanoformate." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/2/12609090/index.pdf.

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Functionalized cyanophosphates are important starting materials for the synthesis of beta-lactam ring moiety of beta-lactam antibiotics. The cyanophosphates are synthesized starting from easily available acylphosphonate and ethylcyanoformate. Acylphosphonates are synthesized starting from acylchloride and trimethylphosphite. Addition of acylphoshonate to ethylcyanoformate furnishes the cyanophosphate with the quaternary center.

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24

Knott, Kerstin. "Iron-mediated Synthesis of the Antiostatins." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2009. http://nbn-resolving.de/urn:nbn:de:bsz:14-ds-1237582907592-42405.

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Within this thesis the first total syntheses of eight biologically active natural products from the family of carbazole alkaloids, antiostatins A1 to A4 and B2 to B5, were established. Spectroscopic data of the synthesised natural products are in good agreement with the isolated antiostatins from Streptomyces cyaneus 2007-SV1, which confirms the molecular structures assigned to the natural products. The total synthesis of the antiostatins A1 to A4 and B2 to B5 were achieved employing the iron-mediated synthesis to form the carbazole nucleus from a cyclohexadienylium iron salt and appropriate arylamines. This transition metal-mediated approach could be applied to all antiostatins in excellent yields. The antiostatins A1-4 and B2-5 represent the first carbazole alkaloids with an acetamide or substituted biuret chain. Introduction of the sophisticated substituents proceeded selectively on C-4 in high yields. Antiostatins A1 to A4 and B2 to B5 could be synthesised over eight steps from a tricarbonyliron-coordinated cyclohexadienylium salt. The overall yields are in the range of 31 – 63%.

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25

Docherty, Gordon Findlay. "Iron diene complexes in organic synthesis." Thesis, University of Strathclyde, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.367031.

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26

Knott, Kerstin. "Iron-mediated Synthesis of the Antiostatins." Doctoral thesis, Technische Universität Dresden, 2008. https://tud.qucosa.de/id/qucosa%3A24053.

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Within this thesis the first total syntheses of eight biologically active natural products from the family of carbazole alkaloids, antiostatins A1 to A4 and B2 to B5, were established. Spectroscopic data of the synthesised natural products are in good agreement with the isolated antiostatins from Streptomyces cyaneus 2007-SV1, which confirms the molecular structures assigned to the natural products. The total synthesis of the antiostatins A1 to A4 and B2 to B5 were achieved employing the iron-mediated synthesis to form the carbazole nucleus from a cyclohexadienylium iron salt and appropriate arylamines. This transition metal-mediated approach could be applied to all antiostatins in excellent yields. The antiostatins A1-4 and B2-5 represent the first carbazole alkaloids with an acetamide or substituted biuret chain. Introduction of the sophisticated substituents proceeded selectively on C-4 in high yields. Antiostatins A1 to A4 and B2 to B5 could be synthesised over eight steps from a tricarbonyliron-coordinated cyclohexadienylium salt. The overall yields are in the range of 31 – 63%.

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27

Robinson, Emily R. T. "α,β-unsaturated acyl ammonium intermediates in asymmetric organocatalysis." Thesis, University of St Andrews, 2015. http://hdl.handle.net/10023/7010.

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This thesis details investigations into the generation and synthetic utility of α,β-unsaturated acyl ammonium intermediates using isothioureas as Lewis base organocatalysts to generate a range of heterocyclic products. Initial investigations focussed on the development of a Michael addition-lactonisation protocol utilising α,β-unsaturated acyl ammonium intermediates (generated in situ from HBTM 2.1 and α,β-unsaturated homoanhydrides) and a range of 1,3-dicarbonyl nucleophiles. Products could be isolated as lactones or as ring-opened highly functionalised esters, giving good yields and excellent enantioselectivity. 1,3-Diketones were shown to generate a mixture of regioisomers and whereas 1,3-ketoesters afforded only a single regioisomer. A crystal structure of an α,β-unsaturated acyl ammonium intermediate was obtained that clearly demonstrated steric blocking of the Si- face of the alkene by the catalyst stereodirecting groups, therefore it can be postulated that enantiocontrol in the addition occurs by selective nucleophilic addition from the Re- face. α,β-Unsaturated acyl ammonium species were then shown to participate in asymmetric annulation processes with benzazole nucleophiles to afford highly functionalised heterocyclic products, with both lactone and lactam formation observed. The relationship between nucleophile structure and process regioselectivity was investigated and it was demonstrated that benzothiazole and benzimidazole nucleophiles afforded preferential N-cyclisation to give lactams whilst benzoxazoles exhibited O-cyclisation to form lactones. It was also possible to influence the regioselectivity by changing the electronic properties of the acyl group (R'). Due to the reactivity of this class of nucleophiles it was possible to access products with quaternary centres. Palladium-catalysed cross coupling reactions were also successful on 3-bromo substituted lactams, demonstrating the potential for further derivatising these interesting heterocyclic products. Finally, a cascade protocol was developed that employed Michael-Michael-lactonisation steps to give tricyclic products from enone malonate nucleophiles and α,β-unsaturated acyl ammonium intermediates (generated in situ by addition of HBTM 2.1 into acid chlorides). Interestingly, the reaction showed higher enantioselectivity at elevated temperatures (70 ˚C) and moderate regioselectivity (1,4- vs. 1,2-addition), which could not be improved after extensive screening. A range of lactones was isolated in moderate yields and enantioselectivity.

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28

Patel, Divya. "The synthesis and rearrangement of N-alkyl-O-acyl hydroxamic acid derivatives." Thesis, University of Warwick, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.400109.

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29

Grant, Seth W. "An Acyl Radical Cascade Model for the Total Synthesis of Lyconadin A." BYU ScholarsArchive, 2005. https://scholarsarchive.byu.edu/etd/759.

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Lyconadin A (1) is a structurally unique Lycopodium alkaloid with antitumor properties, isolated from the club moss Lycopodium complanatum. We are developing a synthetic route to 1 based on a novel 7-exo-trig/6-exo-trig acyl radical cascade cyclization. The synthesis of model acyl radical cascade precursor 23 will be presented. Key features of this synthesis include the suppression of competing elimination during the alkylation of a hindered phenethyl bromide and the use of a lactone as a precursor to a compound bearing two differentially protected primary alcohols. An account of our studies on the model acyl radical cascade cyclization (23 to 24 above) will also be given, including a stereochemical analysis of the product. Our findings have been applied to develop a more detailed stereoselective synthetic plan for Lyconadin A (1).

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30

Afeke, Cephas Ofoe. "Chemistry of Acyl Nitrenes in the Synthesis of Carbamates and Complex Heterocycles." Youngstown State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1442410888.

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31

Rusch, Marion [Verfasser]. "Design, synthesis and application of small molecule acyl protein thioesterase inhibitors / Marion Rusch." Dortmund : Universitätsbibliothek Technische Universität Dortmund, 2011. http://d-nb.info/1018126600/34.

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32

Iddon, Lisa. "The synthesis of biological important phase II Metabolites; 1-B-O-Acyl Glucuronides." Thesis, University of Liverpool, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.511038.

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33

Darwish, Moftah. "Iron and ruthenium catalysts for asymmetric synthesis." Thesis, University of Warwick, 2012. http://wrap.warwick.ac.uk/56286/.

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A series of chiral di-, tri- and tetra amine ligands were synthesised from enantiomerically pure 1,2-cyclohexanediamine and 1,2-diphenylethanediamine and, in combination with Ru(II) or Fe(II), employed as asymmetric catalysts in the epoxidation of aromatic alkenes, hydrosilylation of acetophenone, nitro-aldol reaction and asymmetric transfer hydrogenation (ATH) of different ketones. A novel class of tridentate ruthenium catalysts of general structure 239 below were developed. Specifically, a novel class of tridentate ligand was synthesised and a derivative of (R,R)-N-tosyl-1,2-diphenyl-1,2-ethylenediamine ((R,R)-TsDPEN) and was found to provide the best activity and selectivity in reduction reactions with Ru3(CO)12. Reaction conditions were optimised using 239 for the ruthenium-catalysed ATH of a number of ketones. In particular, it was found that the presence of meta-methoxy substituent on the aromatic ring of the substrate yields optimal results under the ATH conditions employed for 48 h (98% conv., 94% ee). Also, aryl ketones substituted at the ortho position were reduced in almost quantitative yield, with enantiomeric excesses greater than 90% in some cases.

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34

Howard, Luciano E. M. "Synthesis and characterisation of iron platinum nanoparticles." Thesis, Durham University, 2007. http://etheses.dur.ac.uk/2442/.

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This thesis investigates the synthesis and characterization of FePt nanoparticles, a material which is a promising candidate for use as an ultra-high density magnetic storage medium; relevant literature is reviewed in chapter one. Chapter two gives full details of the characterisation techniques and physical property measurements employed throughout the work described in the following chapters. This includes powder X-ray diffraction, SQUID magnetometry, transmission electron microscopy, extended X- ray fluorescence spectroscopy and Rutherford backscattering. Chapter three describes the synthesis and characterisation of FePt nanoparticles prepared by a route presented in the literature as well as one developed during this study. Chapter four describes a systematic investigation into the Rietveld refinement of powder X-ray diffraction data of iron platinum nanoparticles. From the study it is concluded which of the methodologies presented is most suitable for use in further work on iron platinum nanoparticle studies. Chapter five describes a number of in-situ variable temperature X-ray diffraction studies designed to investigate the order-disorder transition in FePt nanoparticles. A comparison between this transition in samples made via both synthetic routes discussed in chapter three is made before analysing in-depth data in order to provide information about the phase transition and its relationship with precise synthetic conditions. Chapter six describes work done on FePt nanoparticles to determine if EXAFS measurements can be obtained and modelled such that conclusions can be drawn as to the degree of order of samples prepared via different methods. Chapter seven describes a variety of magnetic studies designed to investigate the structure and properties of FePt nanoparticles. The first part of the chapter focuses on typical experiments and what use they are whilst the second part discusses the methodology and equipment required to study the phase transition of iron platinum nanoparticles, i.e. variable temperature magnetic studies.

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35

Palotai, Ian Michael. "Cyclohexadiene iron complexes in lycorine asymmetric synthesis." Thesis, University of East Anglia, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.328670.

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36

AMORIM, BRUNO VINICIUS DA FONSECA LIMA. "SYNTHESIS AND CHARACTERIZATION OF IRON DISULFIDE (FES2)." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2004. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=6139@1.

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INSTITUTO DE PESQUISA E DESENVOLVIMENTO
O dissulfeto de ferro pode ser aplicado em sistemas de elevado grau tecnológico, por exemplo, componentes em coletores de energia solar, anodo despolarizador para a produção de hidrogênio e material catódico em baterias e pilhas de alta densidade de energia. O presente trabalho apresenta um estudo termodinâmico e cinético da reação de síntese de dissulfeto de ferro em um reator de leito fluidizado para temperaturas variando entre 400ºC e 500ºC, em regime de leito borbulhante. O rendimento da reação de síntese depende fortemente dos valores estabelecidos para as variáveis de processo: vazão de gás de arraste, temperatura, pressão parcial de enxofre gasoso, natureza das matérias-primas e tempo de reação. Em condições mais favoráveis de reação - 60 min e 500ºC - obteve-se conversão em FeS2 acima de 95%, partículas agregadas com distribuição de tamanhos na faixa de 100um a 200 um, de morfologia uniforme e esferoidal. A desagregação manual do FeS2 aglomerado conduz as partículas a tamanhos médios de 1,5um, tamanho considerado ideal para aplicações em fontes eletroquímicas. A quantificação do FeS2 foi realizada através do Método de Rietvelt associado à análise de DRX. Os resultados mostraram que é possível através de uma rota pirometalúrgica inovadora, partindo-se de reagentes relativamente baratos - Fe2O3 e S, obter o FeS2 para aplicação em catodos de pilhas e baterias.
Iron disulfide can be used as an alternative material in high technological systems, as an example, solar energy collectors and cathodic component in primary and secondary batteries. The present work studies the kinetics and thermodynamics of the iron disulfide synthesis in a fluidized bed reactor for temperatures varying from 400ÂºC to 500ÂºC, operating in the bubble fluidized bed regime. It was observed that the synthesis conversion is much dependent on control variables: inert gas flow, temperature, sulfur gas partial pressure, nature of raw materials and reaction time. In favorable experimental conditions, that is 60 minute time reaction and 500ÂºC temperature, it was achieved more than 95% iron oxide conversion in iron disulfide, generating particle aggregates with distribution size between 100Âum and 200Âum, uniform morphology with ellipsoidal appearance. Manual desagragation leads to small iron disulfide particles with 1,4 Âum average size, ideal for electrochemical use. The iron disulfide phase quantification was performanced by the Rietvelt method associated with Powder Difraction technique. The results showed that it is possible, within a pyrometallurgy route, to synthesize iron disulfide for electrochemical applications, from cheap and easy obtainable reagents such as iron oxide and elemental sulphur.

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37

Tang, Yawei. "Synthesis and characterisation of iron-containing perovskites." Thesis, University of Oxford, 2018. http://ora.ox.ac.uk/objects/uuid:993996ed-92ee-4ddf-963d-d98eafc99580.

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In this research project, iron-containing perovskites with the general formulae A₃Fe₂B'O₉, A₂A'Fe₂B'O₉ and A₂A'FeB'B''O₉ have been synthesised using conventional solid-state reactions. A combination of experimental techniques has been applied to characterise the samples. The main aspects studied include their crystal symmetry, cation ordering pattern and magnetic behaviour. We have shown for the first time that Sr₃Fe₂TeO₉ can adopt a trigonal perovskite-like structure with the Fe³⁺ and Te⁶⁺ cations ordering in a 2:1 sequence. However, the trigonal structure is disrupted by both nanotwinning and regions where the cations order in a 1:1 sequence. These disruptions prevent full antiferromagnetic ordering throughout the sample and the unordered spins form a spin-glass phase that coexists below 80 K. The identification of this disorder has allowed us to account for inconsistencies in the existing literature. Ba₃Fe₂TeO₉ is a 6H perovskite in which the cation sites in the face-sharing octahedra and the vertex-sharing octahedra are occupied by different fractions of Fe³⁺. At a temperature close to 300 K the atomic moments begin to order in an antiferromagnetic manner, and the spins that are unable to take part in the long-range magnetic order form clusters that freeze at 18 K. In the series Sr_xBa_3-xFe₂TeO₉ (x=1~2.5), as x decreases the crystal structure switches from purely pseudo-cubic to purely hexagonal via a biphasic region, illustrating the effect of the radius ratio r_A/r_B on crystal structure. A₂LaFe₂SbO₉ (A=Ba, Sr, Ca) and CaLa₂Fe₂SnO₉ have cation disorder on their A sites. Ca₂LaFe₂SbO₉ and CaLa₂Fe₂SnO₉ both adopt a monoclinic P21/n structure and Sr2LaFe2SbO9 adopts a triclinic P -1 structure, all of which show different levels of B-cation ordering. Ba₂LaFe₂SbO₉ has a Pbnm structure with disordered B sites. These perovskites are not paramagnetic at 300 K, and they all adopt a G-type magnetic structure, which leads to long-range ferrimagnetic or weak ferromagnetic behaviour. The three antimonycontaining compounds contain a minor spin-glass-like phase below 50 K, while CaLa₂Fe₂SnO₉ has a relatively well-developed magnetic backbone at 300 K. We found that the six-coordinate cations in the P2₁/n perovskite SrLa₂FeCoSbO₉ order in a previously unreported manner. The observed cation distribution, with diamagnetic Sb⁵⁺ and magnetic Co²⁺ each partially occupying only one of the six-coordinate sites, results in ferrimagnetism below the Curie temperature of 215 K. CaLa₂FeCoSbO₉ and ALa2FeNiSbO9 (A=Ba, Sr, Ca) were prepared as analogues of SrLa2FeCoSbO9, and they have similar crystal structure and high Curie temperatures. However, TEM revealed the different levels of inhomogeneity present in these four compounds. The inhomogeneity is least significant in CaLa₂FeCoSbO₉, and it is most significant in BaLa₂FeNiSbO₉ where both primitive phase and body-centred phases have been observed in a single crystallite. Consequently, doubt has been cast on the interpretation of the diffraction data for these inhomogeneous samples. A₂LaFe₂NbO₉ (A=Sr, Ca) and CaLa₂Fe₂TaO₉ were prepared with d⁰ cations for comparison with the perovskites containing d¹⁰ B-cations. Ca₂LaFe₂NbO₉ and CaLa₂Fe₂TaO₉ adopt the P2₁/n structure, and Sr₂LaFe₂NbO₉ adopts the P -1 structure. These three perovskites show less well-developed ordering pattern than their antimony analogues due to the smaller difference in size of B-cations. They are not simple paramagnets at 300 K, and they all adopt a G-type magnetic structure with long-range ferrimagnetism. However, the formation of magnetic backbone is significantly slowed down from that in the d¹⁰ compounds and the temperature for the paramagnetic spins to freeze is lowered below 20 K. We propose that in these materials a J₃ interaction occurs via the Fe³⁺ - O - Nb⁵⁺/Ta⁵⁺ - O - Fe³⁺ pathway to compete with the dominant J₁ interaction. The J₃ interaction is more significant when d⁰ cations are present because hybridisation of the empty d orbitals and the anion p orbitals facilitates virtual electron transfer.

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38

Mabaso, Evans Itai. "Nanosized iron crystallites for Fischer-Tropsch synthesis." Doctoral thesis, University of Cape Town, 2005. http://hdl.handle.net/11427/8736.

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Includes bibliographical references (p. 131-148).
Fischer-Tropsch synthesis is the production of hydrocarbons from CO and H2. The catalytically active metals for industrial application are cobalt and iron. In this work iron-based catalysts were studied. To ensure maximum metal utilisation and therefore a high weight specific catalytic activity, the metal crystallites should possess large speciﬁc surface areas and that is only achievable with small metal crystallites. However, a minimum crystallite size might exist below which catalyst activity drops. Consequently, in order to investigate the role of crystallite size on the stability, the activity and selectivity of iron based catalysts, supported catalysts with a known narrow metal crystallite size distribution were prepared via precipitation in water-in-oil microemulsions in which water-to-surfactant ratio was the main design parameter. The study was subdivided into firstly characterisation of a suitable water-in-oil microemulsion system. Secondly preparation of nanosized oxidic iron crystallites with controlled crystallite size via precipitation in water-in-oil microemulsion. Thirdly preparation of the supported catalyst using the same but selected microemulsion systems. Finally catalyst testing under Fischer-Tropsch reaction conditions in a ﬁxed bed reactor. A strictly linear relationship between water-to-surfactant ratio and crystallite size was observed. The catalyst preparation technique for unsupported iron oxides resulted in uniform nanocrystallites tailored to a size range of 2-16 nm. The morphology of the crystallites on supports remained largely unchanged upon reductive pretreatment. This made catalysts prepared in microemulsions ideally suitable for investigating the effect of crystallite size during Fischer-Tropsch synthesis.

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39

Lian, Yiqian. "Chromium and iron organometallics in organic synthesis synthetic studies toward total synthesis of taxol and chromium to iron transfer processes /." Diss., Connect to online resource - MSU authorized users, 2006.

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40

Gavaghan, Claire Louise. "Synthesis and reactivity studies of B-1-0-acyl-D-gluconurides of model drugs." Thesis, Birkbeck (University of London), 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.285146.

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41

Salazar, Alvarez German. "Synthesis, characterisation and applications of iron oxide nanoparticles." Doctoral thesis, KTH, Materials Science and Engineering, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-87.

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Further increase of erbium concentrations in Er-doped amplifiers and lasers is needed for the design of efficient, reliable, compact and cost-effective components for telecommunications and other photonic applications. However, this is hindered by Er concentration dependent loss mechanism known as upconversion. The upconversion arises due to non-radiative energy transfer (ET) interactions (migration and energy-transfer upconversion) among the Er ions exited to the metastable level that is used for amplification. The upconversion deteriorates the conversion efficiency of Er doped gain medium and may even totally quench the gain. The upconversion can be significantly intensified if the Er distribution in glass is non-uniform, which can be minimized by optimizing the fabrication process and the glass composition. The optimization requires detailed characterization techniques capable to distinguish between the effects caused by the uniformly distributed ions (homogeneous upconversion, HUC) and non-homogeneously distributed ions (pair induced quenching, PIQ)

The thesis deals with rigorous statistical modeling of the HUC and development of experimental methods that can provide accurate and detailed data about the upconversion, which are needed for the characterization of the upconversion.

The presented model interprets the homogenous upconversion as an interplay of ET interactions between randomly distributed Er ions, which is affected by stimulated emission/absorption of the radiation propagating in the medium. The model correspondingly uses the ET interactions parameters as the main modeling parameters.

The presented analytical model is verified by Monte-Carlo simulations. It explains strongly non-quadratic character of the upconversion observed in experiments and variety of the associated effects. The model is applicable to the interpretation of the upconversion measurements in various experimental conditions, which facilitates the upconversion characterization. The thesis also presents an advanced experimental method for accurate and detailed characterization of the upconversion in both continues-wave pumping conditions and during the decay of Er population inversion. Using the method the upconversion modeling is experimentally verified by correlating the measurements results with the modeling predictions in the whole range of the practical Er doping levels. This also allows to estimate the parameters for the ET interactions in silica. Finally, it is shown that the presented method can serve as a basis for discrimination of HUC and PIQ effects, which is crucial for optimizing the fabrication process and the glass composition.

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42

Salazar-Alvarez, German. "Synthesis, characterisation and applications of iron oxide nanoparticles /." Stockholm, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-87.

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43

Adedeji, Dolapo A. Duin Evert C. "Isoprenoid synthesis new roles for iron sulfur clusters /." Auburn, Ala., 2007. http://repo.lib.auburn.edu/Send%2002-04-08/ADEDEJI_DOLAPO_4.pdf.

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44

Hudziak, Stephen. "Iron-filled carbon nanotubes : Synthesis, characterisation and applications." Thesis, Queen Mary, University of London, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.528419.

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45

Owen, David Alan. "Aryl substituted cyclohexanienyl iron complexes in alkaloid synthesis." Thesis, University of East Anglia, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.278063.

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46

Puntambekar, Shakher Gajanan. "Half-sandwich arene iron complexes : synthesis and reactivity." Thesis, University of Nottingham, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329900.

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47

CORTEZ, ORFELINDA AVALO. "SYNTHESIS AND CHARACTERIZATION OF NANOSTRUCTURED IRON-NICKEL ALLOYS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2008. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=12975@1.

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Abstract:

PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO
COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
Oxido de níquel e hematita nanoestruturadas foram sintetizadas a partir da decomposição térmica de nitrato de níquel hexahidratado e nitrato férrico nonahidratado respectivamente, na faixa de temperatura de 350-450°C com variações no tempo reacional. Os tamanhos de cristalito do NiO e Fe2O3 foram estimados a partir dos difractogramas de Difração de Raios-X (XRD) utilizando os software PowderCell e Topas. Foi observado que o tamanho de cristalito varia em função da temperatura de sínteses. O resultado mais significante foi observado nos cristalitos de NiO os quais aumentam de 31 nm (T=350°C, 3hr) a 98 nm (T=450°C, 5hr). Foram realizados estudos cinéticos da redução NiO e Fe2O3 por hidrogênio na faixa de temperatura de 250-600°C. Ligas ferroníquel nanoestruturadas com composições FexNi100-x (x = 25, 50, and 75 w%) têm sido preparadas com sucesso por decomposição térmica de nitratos (formação de óxidos) e posterior redução com hidrogênio a 700ºC (formação das ligas). As ligas Fe-Ni, caracterizadas por difração de raios-X mostraram tamanhos de cristalito da ordem de 25nm. A fase rica em Ni, liga Fe25Ni75, apresentou uma estrutura γ(FCC). A liga Fe50Ni50 apresentou a existência de uma estrutura tetragonal. A fase rica em Fe, liga Fe75Ni25, contém uma mistura de fases α(BCC) e γ(FCC). A coexistência das fases e atribuída à segregação de fases que acontece nestas ligas como resultado da difusão atômica. A partir dos resultados das medições magnéticas efetuadas a 300K, pode-se estabelecer que as ligas Fe-Ni nanoestruturadas tem um comportamento superparamagnético.
Nickel oxide and hematite nanostructured were successfully prepared by thermal decomposition from nickel nitrate hexahydrate and ferric nitrate nonahydrate in the temperature range of 350-450°C with variation of the time. The average crystallite sizes of NiO and Fe2O3 were estimated from X-ray diffraction (XRD) peaks using the PowderCell and Topas software. We observed that the crystallite size changes as a function of synthesis temperature. The significant result was the large size of the resulting NiO crystallites, which increased from 31nm (T=350°C, 3hr) to 98nm (T=450°C, 5hr). Kinetic studies of the reduction of NiO and Fe2O3 by hydrogen in the temperature range 250-600°C have been investigated. Nanostructured Fe-Ni alloys with compositions FexNi100-x (x = 25, 50, and 75 w%) have been successively prepared by thermal decomposition from mixtures of nitrates (formation of oxides) and reduction by hydrogen at 700ºC (formation of alloys). The Fe-Ni alloys, characterized by X-ray diffraction show crystallites sizes about 25nm. The Nirich phase, Fe25Ni75 alloys show the existence of γ(FCC) phase. The Fe50Ni50 alloy show the existence of tetragonal phase. The Fe-rich phase, Fe75Ni25 alloy, contain a mixture of α(BCC) and γ(FCC) phases. The coexistence of these phases is attributed to phase segregation occurring in these alloys as a result of enhanced atomic diffusion. It was inferred from results of magnetic measurements at 300K, that nanostructured Fe-Ni alloys were in a superparamagnetic state.

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48

Hoff, Richard. "Iron Oxide Nanoparticle Surface Modification: Synthesis and Characterization." Master's thesis, Temple University Libraries, 2019. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/592997.

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Abstract:

Bioengineering
M.S.
Multifunctional nanomaterials can be engineered to aid in the diagnosis of diseases, enable efficient drug delivery, monitor treatment progress over time, and evaluate treatment outcomes. This strategy, known as theranostics, focuses on the combination of diagnostic and therapeutic techniques to provide new clinically safe and efficient personalized treatments. The evaluation of different nanomaterials’ properties and their customization for specific medical applications has therefore been a significant area of interest within the scientific community. Iron oxide nanoparticles, specifically those based on iron (II, III) oxide (magnetite, Fe3O4), have been prominently investigated for biomedical, theranostic applications due to their documented superparamagnetism, high biocompatibility, and other unique physicochemical properties. The aim of this thesis is to establish a viable set of methods for preparing magnetite (iron oxide) nanoparticles through hydrothermal synthesis and modifying their surfaces with organic functional groups in order to both modulate surface chemistry and facilitate the attachment of molecules such as peptides via covalent bond formations. Modifying their surfaces with biomolecules such as peptides can further increase their uptake into cells, which is a necessary step in the mechanisms of their desired biomedical applications. The methods of nanoparticle synthesis, surface functionalization, and characterization involving electron microscopy (e.g., SEM, TEM), zeta potential measurements, size analysis (i.e., DLS), and FT-IR spectroscopy will be presented.
Temple University--Theses

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Saglam, Guluzar. "Synthesis Of Novel Chiral Thiourea Derivatives And Their Applications, Synthesis Of Some Hdac Inhibitors, Addition Of Acyl Phosphonates To Ethylcyanoformate." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/3/12609265/index.pdf.

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The thiourea derivatives have become a main focus of research in asymmetric synthesis as an organocatalyst in recent years. In the first part, the thiourea catalysts are synthesized starting from easily available L-tartaric acid and application of the catalysts to some addition reactions showed no significant asymmetric induction. A number of HDAC inhibitors have been developed as anti-cancer agent at the present time.In the second part, some aryl butenoic acid derivatives are synthesized as HDAC inhibitors starting from substituted benzaldehyde and pyruvic acid. The HDAC activity studies showed comparable results with known molecules. In the last part, some acyl phosphonates are synthesized and addition of ethylcyanoformate to acyl phosphonates furnished the products in good yields.

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50

Zhu, Koudi. "Model Studies Towards the Total Synthesis of Lyconadin A via An Acyl Radical Cascade Reaction." Diss., CLICK HERE for online access, 2006. http://contentdm.lib.byu.edu/ETD/image/etd1364.pdf.

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Dissertations / Theses on the topic 'Synthesis of iron acyl'

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