für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray In order to conserve plant species, there is a need to highlight other important sustainable exploitations of these species by documenting and validating the uses. This study was undertaken to determine the oil content and its characteristics for selected 11 wild plants species chosen because they are among the dominant plant species in the primary forest of Kahuzi-Biega National Park and surrounding areas in Kivu Region, Democratic Republic of Congo. The plant seed oil contents reported in this study were found high compared to some food crops such as soybean and olive seed. Some of the oils of the plants studied here have potential for use in food because of their essential fatty acids content and some other oils showed good promise in use in cosmetics. These plant oils may also be sources for very long chain fatty acids which also have important chemotaxonomic significance. ····· 10361115198
für 71.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Crystal structure plays an important role in determining chemical and mechanical properties of polymers.Elucidating the crystal structure of polymers is extremely difficult particularly in obtaining a sizeable crystal for XRD analysis.This work prove the viability of computer modelling approach interfaced with simulated XRD diffraction. High-performance aromatic polymers based on the 4,4`-biphenylene, 1,3-phenylene,isophthaloyl bis(4,4`-biphenylene) and p-terphenyl units were synthesized and their crystal structures investigated. The polymers show extreme thermal stability and are insoluble in almost all organic solvents.Oligomer and polymer crystal structures were constructed using computational modelling and quantitatively compared with simulated diffraction via Rietveld Analysis. Molecular mechanics force-fields were optimised from conformational and crystal packing data determined from oligomeric analogues by X-ray single-crystal and powder diffraction methods. ····· 10361115195
····· lezzter Preis 53.10€ ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray The extreme cytotoxicity of natural enediyne antibiotics is attributed to the ability of the (Z)-3-ene-1,5-diyne fragment incorporated into a 10- or 9-membered ring cyclic system to undergo Bergman cyclization and producing dDNA-damaging p-benzyne diradical. The rate of this reaction strongly depends on the ring size. Thus 11-membered ring enediynes are stable, 10-membered ring analogs undergo slow cycloaromatization under ambient conditions or mild heating. Very little is known about reactivity of 9-membered ring enediynes due to their instability. We have developed thermally stable photo-precursors of 9-membered enediynes, in which one of the triple bonds is replaced by the cyclopropenone group. UV irradiation of the photo-precursor results in the efficient decarbonylation and the formation of reactive enediyne. The latter undergoes clean cycloaromatization spontaneously with absence of any chemical additives. Synthetic strategies of a series of cyclopropenone containing nine-membered enediyne precursors and DNA-cleavaging activity of the photo-generated enediynes have been also discussed. ····· 10361115101
für 71.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Several approaches to the synthesis of a natural acetyl cholinesterase (AChE) inhibitor, cyclophostin and an isosteric endophosphonate analog were explored. These bicyclic molecules posses a novel seven membered cyclic enolphosphate/phosphonate ring fused to a butyrolactone. Two basic synthetic strategies: a) lactonization followed by the seven membered ring formation and b) the seven membered ring synthesis followed by lactonization, were applied in these syntheses. The synthesis of the endophosphonate analog, following strategy a, gave an unexpected enolether lactone molecule. Alternatively, strategy b successful produced the endophosphonate analog as a separable mixture of two diastereomers. Synthesis of cyclophostin was explored by strategy b. Attempted C-acetylation of an acyclic phosphate intermediate resulted in an unanticipated formation of cyclopropane ring. Following an alternate approach by strategy a, the natural product and its unnatural diastereoisomer were produced. Biological studies with cyclophostin, endophosphonate analog and various synthetic intermediates lead to the discovery of new class of AChE inhibitor. ····· 10361114937
für 71.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray This book is based on a research study in synthesis and characterization, properties and investigation of new monomers and polymers containing electroactive fragments. Some of the derivatives could be used as hole transporting materials as well as hosts in organic light emitting diodes or in electrographic photoreceptors. Also there are presented series of new crosslinkable derivatives their synthesis, characterizaton, preparation and investigation for electroactive polymeric networks. Some of the insoluble electroactive systems are suitable for preparation of multilayer organic light emitting devices. ····· 10361114444
für 61.20€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Diamond display some of the most extreme physical properties even though its practical use in science and engineering has been restricted due its scarcity and expense. With the recent developments of techniques for the deposition of thin films of diamond on various substrates, it is now possible to explore these superior properties in various exciting applications.In this book, we have contributed to the development of easy, controllable and specific surface functionalization methods for the introduction of different functional groups on the diamond surface. These methods are based on chemical, photochemical, and electrochemical concepts. ····· 10361114383
für 71.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray The work describes the isolation of some tetranortriterpenoids from meliaceae family along with their characterization using NMR, Single crystal X-ray Diffraction studies etc. Chemical modifications of some selected molecules have been reported and the antifeedant activity of all molecules have been assayed against spodoptura litura.Finally, some insilico studies were carried out, which pointed to some molecular parameters (descriptors) that might be responsible for the antifeedant activity of these molecules ····· 10361114133
für 61.20€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Through this book, we can see that the synthesis of steroids continuous to be a challenge for many teams of research. Indeed, due to the molecular biology, the bio-chemistry of steroids is going to be better understand. The steroids receptors are going to be better explored. the biological activities of those oxo steroids for which data are available have been given. we note that most of the efforts till now were concentrated on the synthesis of steroids containing a new ring fused to a ring A, ring D are bridging ring A and B ····· 10361113857
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray To enhance the student experience, the University of South Carolina, Department of Chemistry and Biochemistry, has adopted several new experiments into the curriculum of the organic chemistry majors and honors laboratories. Each experiment involves a particular reaction, or reactions, for which the theory is thoroughly explained throughout the body of this text. All work within is the culmination of experimental trial and error in the procedural design of successful, reproducible experiments in organic chemistry. The challenge was to develop successful semimicroscale techniques using only the resources, apparatus, and instrumentation readily available to the students, while confining them to the laboratory time constraints. ····· 10361113474
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray The present work describes synthesis of copper alginate-cotton cellulose and chitosan attached cotton composite fibers and detailed investigation of antimicrobial action against the model bacteria E.coli. The fibers were prepared by different techniques. The resulting fibers were investigated for their biocidal action against E.coli, by using zone inhibition and colonies counting method. Finally, fibers were reduced with sodium borohydride to yield copper nanoparticles- loaded composite fibers and investigated for biocidal action. It was found that these fibers possessed both, the fair mechanical strength and antibacterial action. The extent of biocidal action was found to depend upon the amount of Cu(II) loaded and concentration of alginate into cotton- cellulose fibers. The fibers showed higher Cu(II) release in physiological fluid as compared to distilled water. Copper alginate-cotton cellulose (CACC) fibers show fair mechanical strength and release copper ions in the presence of physiological fluid and protein solution. These fibers have great potential to be used as dressing materials. ····· 10361113375
für 71.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray This book targets a broad readership for young researchers(Postgraduate students) in X-ray crystallography and Quantum Chemistry as it contains a wide and comprehensive coverage of all important aspects of the subject including up-to- date survey of recent revolutionary advances. Molecular structure determination using crystallographic technique of pyrazolo[3,4-d] pyrimidines, naturally occurring drugs as well as synthetic molecular crystals has been discussed.The optimized structures and the electronic properties of the molecules using quantum mechanical methods have also been discussed and results have been compared with crystallographic data, which could enable one to understand and evaluate different quantum mechanical methods. It should be a valuable asset to established researchers in this area due to very detailed explanation of the behavior of aromatic - interactions on the basis of experimental and theoretical results. The crystallographic and theoretical investigations on some synthetic and natural drugs attract the research in the area of drug design using Molecular modeling of the reported compounds with suitable targets. ····· 10361113318
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray In recent years emphasis has been given on effective utilisation of naturally available and renewable resources for the development of raw materials for various polymer based products. Cashew Nut Shell Liquid (CNSL) and one of its ingredients cardanol has been successfully exploited for the development of phenolic resins for the manufacture of different industrial products. Since cardanol is phenol with meta substituted aliphatic unsaturated long chain, it can be properly modified to a high molecular weight nucleophilic compound containing flexible as well as rigid molecular chains. Such a nucleophilic high molecular weight compound can react with a diisocyanate which is an electrophile to give polyurethane. Therefore by carefully synthesising the high molecular weight nucleophilic compound with different molecular size, functionality and structure, it is possible to develop polyurethanes having wide range of physico-chemical and mechanical properties as well as high performance characteristics, such as long term stability under ageing conditions. ····· 10361113300
für 71.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray The inflammation process involves a series of event that can be elicited by numerous stimuli (eg infectious agents, ischemia, and antigen-antibody interaction). The seriousness and enormous after effects of steroid therapy necessitated an accelerated research towards the development of NSAIDs since the past two decades. Quinazoline derivatives have been reported to possess significant activity as anti-inflammatory agents. Triazoles were reported to possess diverse pharmacological activities such as anti-inflammatory activity. In addition, triazine derivatives were found to posses antimicrobial activity. Combining these two structure features in one molecule might produce compounds with promising biological effects. In continuation of my interested research program in design and synthesis of heterocycles containing benzene sulfonamide moieties. In this book, I sought to synthesis and structure elucidation evaluation of some novel anti-inflammatory triazoloquinazoline and triazinoquinazoline having biologically active benzene sulfanilamide moieties. In addition, the acute toxicity of anti-inflammatory compounds was evaluated in order to assess its safety. ····· 10361112940
für 17.00€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Die `Grundlagen der Organischen Chemie` sind als Begleittext für die Grundvorlesung in Organischer Chemie an der LMU München gedacht. Nach einem einleitenden Kapitel zur Bindungssituation in organischen Molekülen werden in der Folge alle wichtigen Stoffgruppen der organischen Chemie besprochen: Alkane, Halogenalkane, Alkene, Alkine, Diene, Aromaten, Alkohole, Ether, Thioalkohole und Thioether, Amine, Aldehyde und Ketone, Kohlenhydrate, Carbonsäuren und Derivate, Aminosäuren, Nucleinsäuren und Isoprenoide. Für alle diese Stoffgruppen werden grundlegende Nomenklaturfragen, Stoffeigenschaften und typische Reaktionsweisen besprochen. Übergreifende Themen werden an geeigneter Stelle in Zusatzkapiteln vorgestellt: Thermodynamik und Kinetik chemischer Reaktionen, Elementaranalyse organischer Verbindungen, optische Aktivität und Stereochemie, Polymere, UV/Vis-Spektroskopie und Chromatographie. ····· 10361108183
für 45.80€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray In this work, investigations and optimizations of the filamentous fungus Caldariomyces fumago as enzyme production host were performed. For UV mutagenesis experiments with C. fumago, UV irradiation parameters were determined. A survival curve was recorded and an irradiation time of 4 min was chosen for all following UV experiments leading to a survival rate of 21 %. By colony screening of randomly mutagenized C. fumago cells 6 albino (white) mutants displaying a slight growth reduction on solid media were isolated. In production media these strains were red-colored due to the production of the heme-containing chloroperoxidase (CPO). Their culture supernatant samples lacked the intense black fungal pigment thereby enabling to follow the formation of CPO by visual inspection of the medium color and simplifying downstream processing. Surprisingly, elimination of the undesirable pigmentation was accompanied by improved CPO secretion. Namely, the CPO content in the culture supernatant samples of the white C. fumago mutants increased significantly faster compared to the wild type. To examine the nature of the black pigment of the C. fumago wild-type strain several inhibitors commonly used to block the synthesis of different pigment in fungi were tested. The addition of 50 µg ml-1 tricyclazole, a specific inhibitor of the 1,8-dihydroxynaphthalene (D2HN) melanin synthesis pathway, induced a significant color change of the C. fumago wild type mycelium proposing the black pigment of C. fumago to be D2HN melanin. A further C. fumago mutant was isolated which was slightly greenish on fructose minimal medium and grew slower in comparison to the wild type. The supernatant sample lacked the Soret band typical for the heme group of the CPO and nearly no CPO activity could be detected. SDS-PAGE analysis of mutant culture supernatant sample showed production of a 38 kDa protein while wild type samples contain the 42 kDa CPO protein. Protein identification using nanoLC-ESI-MS/MS was performed and based on 3 peptides the protein was identified as CPO. In addition, the CPO gene was sequenced. However, no differences in the CPO gene sequence of wild type and mutant were found indicating a post-translational defect in protein maturation. Deglycosylation experiments using CPO from wild type and cpo1 were carried out. After removing N-linked oligosaccharides from wild type CPO a protein band at 38 kDa was detected. These results reveal that the mutant protein lacks the heme group as well as the N-glycans. Addition of different amounts of tunicamycin, an antibiotic that blocks N-linked glycosylation of proteins, to C. fumago wild type cultures did either lead to a strong reduced growth behavior when a too high concentration was applied or had no influence on CPO activity and no visible change in protein size on SDS-PAGE gels was obtained. To select transformants of C. fumago for the development of more efficient transformation systems based on auxotrophic markers the URA3 gene encoding 5`-orotidine monophosphate decarboxylase (OMPD) was chosen. Mutants lacking OMPD activity could be easily selected after UV irradiation since they are able to grow in the presence of 5-FOA but require the addition of uracil or uridine to the medium. Fifty-three strains were isolated and their growth properties were examined by plating on different media. Three strains showed the growth properties which are dedicated to uracil or uridine auxotrophic mutants having a defective URA3 gene. Those cells were transformed with a plasmid containing the URA3 gene either of A. nidulans or C. fumago. However, no complementation of the auxotrophy of any of the 3 strains was achieved. Since mutants with a defective URA5 gene also show the determined growth properties it was assumed that the URA5 gene is affected. Experiments of expressing horseradish peroxidase (HRP) and the carotenoid cleaving peroxidase MsP2 from Marasmius scorodonius using the highly efficient and specific secretion apparatus of C. fumago were performed. Due to the lack of CPO knock-outs strains, the C. fumago wild type strain had to be used in the present work. The construct for the expression of HRP consisted of the N-terminal signal peptide of CPO and the C-terminal propeptide of CPO. The constructs for MsP2 consisted either of the N-terminal secretion signal of CPO or of MsP2 and the C-terminal propeptide of CPO was absent or present. The constructs were transformed into the rDNA region of the C. fumago genome. For all constructs of both enzymes no visible protein bands were detected on SDS-PAGE gels. Enzyme assays specific for HRP and MsP2 were developed. However, no enzyme activity was detected for exemplarily chosen transformants. Several limits of heterlogous gene expression using C. fumago are discussed. ····· 10361107991
für 49.80€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Die große Herausforderung in der chemischen Synthese liegt in der effizienten Darstellung gewünschter Produkte bei gleichzeitiger Minimierung des Energieaufwandes und chemischer Abfälle, was sich insbesondere auf die Ökonomie und Ökologie industrieller Prozesse auswirkt. Der Einsatz von Katalysatoren ermöglicht viele, thermisch nur schwer zu realisierende, chemische Umsetzungen in hoher Effizienz, indem sie Aktivierungsbarrieren verringern und milde Reaktionsbedingungen, sowie eine hohe Produktselektivität und Ausbeute ermöglichen. Vorteilhafterweise werden oft nur sehr geringe Mengen an Katalysator benötigt und dieser durch die Reaktion selbst nicht verbraucht, sondern höchstens mit der Zeit desaktiviert. Eine weitere Möglichkeit chemische Abfälle und Energiekosten zu reduzieren stellt die Anwendung von Eintopfsynthesen dar, bei der mehrere chemische Reaktionen zu Sequenzen zusammengefasst werden, sodass die einzelnen Transformationen im gleichen Reaktionsgefäß kontrolliert ablaufen. Mittels dieses Verfahrens ist es möglich auf die Isolierung von Zwischenprodukten und damit auf die Anwendung von sehr kostenaufwändigen physikalischen Trennoperationen zu verzichten. Florian Erver stellt in diesem Buch eine ganze Reihe Cobalt-katalysierter Reaktionen vor, welche die einfache aber sehr selektive Addition von simplen und zumeist kommerziell verfügbaren Startmaterialien wie Acrylaten, Alkinen, Alkenen, Dienen und Aldehyden zu komplexen, organischen Bausteinen erlauben. Die eingesetzten Cobalt-Komplexe zeichnen sich dabei durch ihren sehr einfachen Aufbau, ihre somit gute Verfügbarkeit, sowie ihre sehr gute Lagerstabilität und Handhabbarkeit aus. In dieser Arbeit werden nicht nur innovative und schnelle Wege zu Heterocyclen, Polyenen und komplexen, tricyclischen Systemen präsentiert, sondern auch neuartige Mehrkomponentenreaktionen vorgestellt. Die Kombination des Prinzips der Eintopfsynthese mit dem der Katalyse führte schließlich zum Konzept der multiplen Cobaltkatalyse, mittels derer bis zu fünf verschiedene Komponenten in einer Sequenz bestehend aus vier Transformationen selektiv unter Ausbildung von fünf C-C-Bindungen zu einem einzigen Produkt verknüpft werden konnten. Desweiteren wird in diesem Buch die erste Synthese der beiden Naturstoffe Credneramid A und B, sowie ihrer biologischen Vorstufe, Crednersäure, vorgestellt. Nachdem Anfang des Jahres 2012 von ihrer Isolation und Strukturaufklärung, sowie ihrer biologischen Aktivität berichtet wurde, stellt der Autor in diesem Buch gleich zwei verschiedene, sehr kurze und effiziente Synthesewege vor, bei der die Anwendung zweier homogener Katalysatoren in Wettbewerb gesetzt wird. Leser mit Interesse auf dem Bereich der organischen Chemie, insbesondere auf dem Gebiet der homogenen Katalyse, der Eintopfreaktionen, sowie der Naturstoffsynthese, werden an diesem Buch viel Freude haben. ····· 10361107628
für 45.80€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Die vorliegende Arbeit befasst sich mit der Darstellung, dem Koordinationsverhalten und den grundlegenden Reaktivitätseigenschaften von Calciumallylverbindungen. Beispiele für katalysierte Reaktionen werden diskutiert, um das Anwendungsspektrum abzuschätzen. Der erste Teil beschreibt die Darstellung von 1-Alkenylkomplexen von Calcium, sowie deren Strukturmerkmale in Lösung und im Festkörper. Modellreaktionen mit CO2, Carbonylverbindungen und Iod zeigen eine hohe Reaktivität gegenüber Elektrophilen auf. Die Isolierung eines Alkylkomplexe wird kurz beschrieben. Der zweite Teil legt das Koordinationsverhalten von Bis(allyl)calcium in der Gegenwart von (Aza)Kronenethern dar. Trotz der Isolierung eines außergewöhnlichen Kronenetheraddukts mit einem s- und einem p-gebundenen Allylliganden im Festkörper, resultiert die hohe Basizität in rascher Zersetzung durch Etherspaltung. Der dritte Teil dieser Arbeit berichtet über Reaktionen von Bis(allyl)calcium mit Brønstedund Lewis-Säuren und die in situ Erzeugung von Calciumallyl-Monokationen. Während Verbindungen des [Ca(C3H5)]+-Kations leicht zu generieren sind, wird deren Isolierung durch schnellen Ligandenaustausch zugunsten der homoleptischen Spezies verhindert. Ein kurzer Vergleich der Aktivität in der Olefinpolymerisation ist gegeben. Der Grundtyp, Bis(allyl)calcium ist aktiv in der Polymerisation von 1,3-Butadien, jedoch nicht in der Polymerisation von Ethylen. Ionenverbindungen des Calciumallyl-Monokations zeigen in den gleichen Reaktionen keine Polymerisationsaktivität. Der vierte Teil beschäftigt sich mit der Reaktivität von Bis(allyl)calcium gegenüber Pyridin, Furan und ihren Derivaten. Eine Serie von Insertions- und C-H Bindungsaktivierungsprodukten wurde durch die Reaktion mit N-Heteroaromaten isoliert. Die Produkte wurden charakterisiert und ihr Bildungsmechanismus zeugt von einer ausgeprägten Balance zwischen Nukleophilie und Basizität der eingesetzten Calciumverbindungen. Die Reaktivität gegenüber Furanen ist undefiniert und resultiert in der Bildung einer Mischung unbekannter Produkte. Der letzte Teil dieser Arbeit beschreibt die Reaktivität von Calciumallylkomplexen gegenüber Diwasserstoff, Silanen und anderen Hydridtransferreagentien. Ein Augenmerk wird auf die Isolierung und Charakterisierung eines kationischen Calciumhydridclusters mit einem hypervalenten Hydridosilikat-Anion gesetzt. Die Reaktion zu einem Ketylradikalkomplex deutet auf eine Aktivität in redox-Reaktionen hin. Diese außergewöhnliche Verbindung katalysiert die Hydrierung eines endständigen Olefins mit H2 unter milden Bedingungen. ····· 10361107608
für 48.80€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Die Lebensdauer von Elastomeren auf Basis von Polydienen wird maßgeblich durch thermisch-oxidative Alterungsprozesse bestimmt. Um die zeitabhängige Funktionsfähigkeit und Lebensdauer von Elastomeren richtig einzuschätzen und verbessern zu können, besteht deshalb großes Interesse an der Charakterisierung der kinetik und an mechanistischen Erkenntnissen zur oxidativen Alterung. Dafür wird in dieser Arbeit die im Bereich der Elastomere selten eingesetzte Messmethode der Chemilumineszenz (CL) eingesetzt. Die Methode nutzt die Emission von Lichtquanten, welche im Verlaufe der Oxidation von Polymeren durch intermediär gebildete Spezies entstehen. Die emittierte Lichtintensität ist mit der Konzentration der betreffenden Spezies im angeregten Zustand propoertional. Daher kann sowohl der Anfangszustand als auch der Verlauf der oxidativen Prozesse über dieses Prinzip erfasst werden. Mit der Methode kann die Stabilität eines Polymers durch den OIT-Wert (oxidation induction time) quantitativ ermittelt und die Kinetik der Oxidationsreaktion festgestellt werden. ····· 10361107384
für 49.80€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Der über die letzten Jahre immer häufigere Nachweis außergewöhnlicher biologischer Aktivitäten hat marine Naturstoffe in den Fokus der Forschung gerückt. Unter diesen Stoffen stellen die ausschließlich in marinen Schwämmen vorkommenden Pyrrol-Imidazol-Alkaloide mit ihren bis heute bekannten 120 Vertretern eine der größten Alkaloidklassen dar. Zwischen 2004 und 2009 wurde diese Klasse durch die Isolierung von neunzehn neuen Verbindungen, die unter dem Gruppennamen der Nagelamide zusammengefasst wurden, erweitert. Viele dieser Nagelamide zeigen antibakterielle, fungizide oder gegenüber der Proteinphosphatase 2A inhibitorische Wirkung. Um eine späte, in früheren Synthesen von Pyrrol-Imidazol-Alkaloiden dann unmögliche Einführung der 2-Aminogruppe zu vermeiden, wurden zwei neue Imidazolbausteine synthetisiert, die bereits eine geschützte 2-Aminogruppe aufweisen. Mit diesen Bausteinen konnten in Pd-katalysierten Kreuzkupplungen neben dem Tautomer von Hydroxyoroidin auch neue Derivate der unbekannten 2-Aminourocaninsäure in guter Ausbeute erhalten werden. Diese konnten zwar in Diels-Alder-Reaktionen als Dienkomponente eingesetzt oder durch Bestrahlung in ihre Z-Isomere überführt, jedoch nicht dimerisiert werden. Versuche, die Bis(imidazolyl)-Teilstruktur der Nagelamide durch metallorganische Kupplung eines 4-Acylimidazols und 4-lod-5-vinylimidazols aufzubauen, stellten sich unter den gewählten Bedingungen als schwierig heraus. Eine doppelte Grignard-Reaktion an unterschiedlich geschützten lodimidazolen lieferte schließlich Bis(imidazolyl)carbinole in sehr guten Ausbeuten. Maßgebliche Erweiterungen und zahlreiche Optimierungen ermöglichten die Synthese von Bis-(2-aminoimidazolyl)propenen in nur fünf Stufen mit einer Gesamtausbeute von bis zu 27%. Die Darstellung dieser Teilstrukturen könnte neben einem schnellen Zugang zur ersten Totalsynthese mehrerer Nagelamide auch Ausgangspunkt für einen neuen Zugang zu anderen Alkaloiden ähnlicher Struktur - z. B. dem Ageliferin - sein. ····· 10361107378
für 61.20€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray The conventional cationic surfactants existing in the field of fabric softeners are diminishing worldwide on account of stringent environmental regulations. It is, therefore, need of the hour to synthesize fabric softening cationic molecules which shall impart remarkable softening and possess rapid and complete biodegradability. Esteramide quaternaries are, therefore, gaining edge over existing cationic species for fabric softening. The aim of the book is to provide latest information on synthesis and characterization of piperazine based esteramide quaternaries from renewable fatty feed stock. The physico-chemical and surface active properties of esteramide quats have also been studied thoroughly. Furthermore, development of cost- effective softeners derived from cheaper fatty acids has been emphasized. ····· 10361102998
für 53.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Organic nanoparticles have attracted tremendous research interests over the past few years owing to their special properties which lie between the properties of molecules and those of bulk material. The electronic properties of organic nanoparticles differ fundamentally from those of inorganic ones. Organic nanocrystals allow much increased variability and flexibility in synthesis of materials, preparation of nanoparticles, and investigation of their physico-chemical properties. The ordered periodic mesoscopic materials allow the construction of composites with many guest types like organic molecules or polymers. These guest/host materials combine high stability of the inorganic host system, new structure forming mechanism due to the confinement of guests in well-defined pore channels. This book consists of two parts. The first part of this study constitute synthesis and photophysical characterization of fluorescent organic nanoparticles of conjugated compounds and rod-coil molecules. The second part deals with the self-assembled organic-inorganic functional hybrid nanocomposites. This book is useful for the materials scientists and for inter-disciplinary research. ····· 10361102973
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray The influence of introducing 1,3,4-thiadiazole and phthalyl groups as a pending groups into the repeating unit of PVC has been studied on the bases of photostability measurements. The photostability of modified. polymers were studied by monitoring the carbonyl Index, polyene index and hydroxyl index, All results obtained indicated that PI, PII, PIII, PIV and PV gave lower growth rate of ICO, IPO and IOH with irradiation time with respect to unmodified PVC film (control). The following trends of photostability are obtained PIPIIPIIIPIVPV According to the experimental results several reaction mechanisms were proposed depending on the presence of 1,3,4-thiadiazole and phthalyl groups moieties in the polymer chain. The mode of chain scission was also investigated by measuring the variation of average viscosity molecular weight with irradiation time for modified PVC. The degree of deterioration ( ) and the average number of chain scission (S) values were also calculated. ····· 10361102672
für 53.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray The synthesis part of this work is divided into three different parts: Part One: This part involved the synthesis of 3-biphenyl-4-ylimidazo[1,2-a]pyridine [1], 3-phenylimidazo[1,2-a]pyridine [2], and other compounds, directly from the starting material. Part Two: This part involved the synthesis of N-carbamoyl-N2-pyridin-2-ylglycinamid [12], N-(4-biphenyl-4-yl-1,3-oxazol-2-yl)-N2-pyridine -2-ylglyciamide [13], and other compounds, from the reaction of 2-aminopyridine with ethylchloroacetate to yield ethyl-N-pyridin-2-ylglycinate [11], this compound was used as precursors. Part Three: This part involved the synthesis of 2-[(pyridine-2-ylamino)methyl]-4,5-dihydro-6H-1,3,4- oxadiazine-6-one [17], 3-[(pyridine-2-ylamino)methyl]1,6-dihydro-1,2,4- triazin-5(2H)-one [18], 5-[(pyridine-2-ylamino)methyl]-1,3,4-oxadiazole-2- thiol [19], and other compounds, starting from 2-(pyridine-2-ylamino)acetohydrazide [16]. This compound was prepared from refluxing ethyl-N-pyridin-2-ylglycinate [11] with hydrazine hydrate. ····· 10361102618
für 44.10€ kaufen ···· Rheinberg-Buch.de - Bücher, eBooks, DVD & Blu-ray Surfactants have many uses in textile processing, used as wetting agents, detergents, emulsifiers, dispersing agents etc. and can be used universally under all conditions. Textile is versatile, therefore processes are conducted in type of conditions, being highly acidic to highly basic, room temperature to as high as 220oC in thermosol dyeing, also can start form acidic pH and end at alkaline pH. Therefore it is needed to formulate a universal chemical which can be work equally well under all process conditions. Surfactants can be ionic and non-ionic, advantage of nonionic being that they can be used under basic and acidic conditions as well as water hardness, but lacks the resistance against temperature. Ionic has the advantage of aqueous solubility under higher temperature, but lacks the flexibility of being used under all pH values and resistance against water hardness. Therefore, we have proposed of substituting organic solvents to surfactants. ····· 10361102279· 1 ·· 2 ·· 3 ·· 4 ·· 5 ·· 6 ·· 7 ·· 8 ·· 9 ·
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