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This study aimed for the synthesis of 4-Aryl-2-amino-6-(4-hydroxy coumarin-3-yl) pyridine-3-carbonitriles derivatives 4, suitable for use as antibacterial, anti-oxidant and anti-inflammatory activities via a versatile, readily accessible 3-((2E)-3(aryl)prop-2-enoyl)-2H-chromen-2-one, 3, which was prepared by refluxing 3-acetyl-4-hydroxycoumarin with aromatic aldehydes in chloroform in the presence of a catalytic amount of piperidine. Then the dir... This study aimed for the synthesis of 4-Aryl-2-amino-6-(4-hydroxy coumarin-3-yl) pyridine-3-carbonitriles derivatives 4, suitable for use as antibacterial, anti-oxidant and anti-inflammatory activities via a versatile, readily accessible 3-((2E)-3(aryl)prop-2-enoyl)-2H-chromen-2-one, 3, which was prepared by refluxing 3-acetyl-4-hydroxycoumarin with aromatic aldehydes in chloroform in the presence of a catalytic amount of piperidine. Then the direct reaction of the obtained chalcones 3 with malonitrile in the presence of ammonium acetate in one step gave products 4. Most of the new compound 4 exhibit moderate antibacterial activity against Gram Negative bacterial strains (E. coli, K. pneumonia, S. typhi and S. flexneri). In addition, the compounds 4 were investigated for anti-oxidant activities by super oxide radical, DPPH (2,2-Diphenyl-1-picrylhydrazyl), and hydroxyl radical scavenging assays, where most of the compounds displayed significant antioxidant activities. Furthermore, these 4-Aryl-2-amino-6-(4-hydroxy coumarin-3-yl) pyridine-3-carbonitriles 4 were evaluated for anti-inflammatory activity by indirect haemolytic and lipoxygenase inhibition assays where compounds revealed good activity. The preparation of novel metal-free phthalocyanines and metallophthalocyanine complexes 11 and 12 (MPcs, M = Co, Zn, Cu and Mn), with four peripheral 6-hydroxy-4-methylcoumarin and 6-hydroxycoumarin substituents, were also prepared by cyclotetramerization of compounds 7 and 10 with the corresponding metal salts (Zn(OAc)2.2H2O, Co(OAc)2.4H2O, CuCl, Mn(OAc)2.4H2O) as a template for macrocycle formation in 2-(N,N-dimethylamino)ethanol.The electronic spectra of these compounds exhibit a band of coumarin identity together with characteristic bands of the phthalocyanine core. The new compounds were screened for antibacterial activity. Most of them are active against E. coli and S. aureus. In addition, some novel 3-acetylcoumarin derivatives 17 were prepared in good yields. Their in vitro antioxidant activities were assayed by the quantitative 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity method. In this way, novel coumarin phtalonitriles derivatives 42-44 were synthesized.The synthesis of these coumarin phtalonitriles was resulting from a nucleophilic aromatic substitution reaction between 4-nitrophtalonitrile and coumarins derivatives. The complexing properties of the coumarin derivatives toward alkali metal, alkaline earth metal, some transition metals and some heavy metal cations have been investigated in acetonitrile by means of UV spectrophotometry absorption and conductivity methods. Thus, the stoichiometry of the complexes formed and their stability constants were determined. We report also in this book chapter a sequence of two ruthenium-catalyzed transformations, namely olefin cross metathesis with allylic chloride followed by elimination, which gives a straightforward access to terminal 1,3-dienes from natural products. The structures of all the new obtained compounds were confirmed by elemental analysis, IR, and multinuclear/multidimensional NMR spectroscopy (1H, 13C-NMR, NOESY, HMBC) which allowed assignment of the complete network of proton and carbon atoms). Show more Show less

Composites with interpenetrating metal-ceramic microstructures (IPC, interpenetrating composites) can be tailored for specific applications, such as high thermal conductivity combined with low thermal expansion, e.g. for heat sinks. Heat sinks are required in power electronic devices or in future fusion reactor technology where extreme conditions and high cyclic thermo-mechanical loads appear. Due to its rigid ceramic backbone IPCs are expected t... Composites with interpenetrating metal-ceramic microstructures (IPC, interpenetrating composites) can be tailored for specific applications, such as high thermal conductivity combined with low thermal expansion, e.g. for heat sinks. Heat sinks are required in power electronic devices or in future fusion reactor technology where extreme conditions and high cyclic thermo-mechanical loads appear. Due to its rigid ceramic backbone IPCs are expected to reveal high thermal stability. Pure silicon carbide exhibits high thermal conductivity, low coefficient of thermal expansion, high corrosion and wear resistance. But it is also known as a very brittle material when mechanical loads are applied. Thus a composite of silicon carbide with ductile and highly conductive copper seems to be a promising new material for a number of applications.This paper reports the synthesis of Cu-SiC composites using a unique high temperature squeeze casting process (HTSC). Microstructural design of SiC-preforms with open porosity and its synthesis progress is reported. Influence of preform properties, temperature, pressure and atmosphere during HTSC were investigated. A qualitative and quantitative description of the microstructure of the composites and their composition allows the creation of structure-property correlations that take effect retroactively to the casting process. Show more Show less

The experimental results prove the ability to produce layers modified by microalloying with electron-beam technology using wide range of materials. Such layers were produced due to initiating exothermic chemical reactions between the base and the thin film covered the base. This resulted in finding new phase compounds in reaction products.

Iron-containing SiC ceramics have low specific resistivity and excellent electromagnetic properties. In this work, hyperbranched polyferrocenylsilane as the precursor of Fe/Si/C ceramics was prepared by the reaction of ferrocenyl dilithium, dichlorodimethylsilane and trichloromethylsilane. The ceramization process of the preceramic polymer from organic to inorganic was then investigated. Precursor microspheres were prepared by emulsion method, wh... Iron-containing SiC ceramics have low specific resistivity and excellent electromagnetic properties. In this work, hyperbranched polyferrocenylsilane as the precursor of Fe/Si/C ceramics was prepared by the reaction of ferrocenyl dilithium, dichlorodimethylsilane and trichloromethylsilane. The ceramization process of the preceramic polymer from organic to inorganic was then investigated. Precursor microspheres were prepared by emulsion method, which were then pyrolyzed to obtain Fe/Si/C ceramic microspheres.The composition, structure and morphologies of the precursor and ceramics were characterized by 1H-NMR, FT-IR, TG-MS, XRD, SEM and EDS. Experimental results showed that the hyperbranched precursor was successfully synthesized, the pyrolytic process of which started at 350 °Cand almost completed above 600 °C. There was crystalline transformation from Fe5Si3 to Fe3Si as the sintering temperature increased from 1000 °C to 1400 °C. Moreover, the crystalline phase of ß-SiC appeared at 1400 °C. Precursor microspheres were prepared by emulsion method. Porous ceramic microspheres were obtained after the precursor microspheres being sintered at 1400 °C, which can be applied in gas adsorption and catalyst supports. Show more Show less