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The bis(imino)quaterpyridine, 6,6"'-{(2,4,6-i-Pr_3C_6H_2)N=CMe}_2-2,2':6',2":6",2'"-C_(20)H_(12)N_4(L_(tripp)), canbe prepared in good yield by the condensation reaction of 6,6"'-bis(acetyl)quaterpyridine with2,4,6-triisopropylani...
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The bis(imino)quaterpyridine, 6,6"'-{(2,4,6-i-Pr_3C_6H_2)N=CMe}_2-2,2':6',2":6",2'"-C_(20)H_(12)N_4(L_(tripp)), canbe prepared in good yield by the condensation reaction of 6,6"'-bis(acetyl)quaterpyridine with2,4,6-triisopropylaniline; the 2,6-diisopropylphenyl derivative 6,6"'-{(2,6-i-Pr_2C_6H_3)N=CMe}_2-2,2':6',2":6",2"'-C_(20)H_(12)N_4(L_(dipp)) is also reported. Reactions of L_(tripp)with 2.5 equivalents of MX_2(MX_2= CoCl_2, CoBr_2, (DME)_2NiCl_2and FeCl_2) in n-butanol at 100 °C overnight results inself-assembly to form the paramagnetic salts [(L_(tripp))M_2X_3]_2[MX_4] [M = Co, X = Cl (1a);M= Co,X =Br (lb); M = Ni, X = Cl (2); M = Fe X = Cl (3)] in moderate yield. The molecular structures ofthe acetonitrile/water adducts 1a(NCMe)_2, 1b(NCMe)(OH_2) and 2(NCMe)_4reveal that L_(tripp)acts as abis(tridentate) ligand that can support a range of structural motifs for the cationic units including[(L_(tripp))CoCl(μ-C1)CoCl(NCMe)]~+, [(L_(tripp))CoBr_2CoBr(OH_2)(NCMe)]~+,[(L_(tripp))CoBr(μ-Br)CoBr)]~+ and[(L_(tripp))NiCl(NCMe)(μ-C1)NiCl(NCMe)]~+. On activation with MAO (methylaluminoxane), 1-3 showmodest activities for ethylene oligomerisation (1a/MAO - lb/MAO > 2/MAO) or are inactive(3/MAO). Notably, the two cobalt systems (la/MAO, lb/MAO) afford highly linear a-olefins whilethe nickel system (2/MAO) yields methyl-branched waxes composed of mostly internal unsaturationalong with lower levels of α-olefins. In addition to 1a(NCMe)2, 1b(NCMe)2(OH2) and 2(NCMe)3, asingle crystal X-ray determination has been performed on the structurally related salt[(L_(tripp))Ni_2Br_3(OH_2)_2][Br] (4).
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In this work, we have synthesized a series of novel porphyrin derivatives, 1-5, in high yields. The metal complexes of two of the newly synthesized porphyrin derivatives, 1a-d and 2a-d, have also been synthesized in high yields an...
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In this work, we have synthesized a series of novel porphyrin derivatives, 1-5, in high yields. The metal complexes of two of the newly synthesized porphyrin derivatives, 1a-d and 2a-d, have also been synthesized in high yields and characterized. In the synthesis of the new porphyrins and metalloporphrins, we employed our reported strategy in which we utilized N,N-dimethylformamide (DMF) as a capping agent in the reaction of pyrrole with different hetero-aryl aldehydes. The new porphyrin derivatives are equipped with different aromatic substituents and hetero-cycles at the peripheral position. The structures of the new compounds were confirmed by elemental and spectral analyses. The geometry and magnetic properties of the new metalloporphyrins 1a-d and 2a-d have also been studied. Antioxidant and cytotoxic activities of the new compounds were evaluated and structure-activity relationships were performed. Porphyrin derivatives 2a and 4 showed exceptional antioxidant activity compared to ascorbic acid as a reference. While the derivatives 2, 3, and 5 exhibited very strong cytotoxic activity against two human cell lines, HePG-2 and MCF-7. Docking for the most promising antioxidant porphyrins, 2a and 4, into the binding active site of antioxidant protein Human Peroxiredoxin (code: 1HD2) has been carried out to detect the degree of recognition antioxidant activity. Molecular docking of the most cytotoxic active porphyrins, 3 and 5, into the biding site of telomerase inhibitor enzyme has been carried out to assess the degree of recognition cytotoxic activity.
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HYDROGELS based on acrylamide and sodium acrylate have been prepared by the chemical initiation and gamma radiation methods. The chemical method was used in presence of ammonium persulfate at 30 oC, whereas, the gamma irradiation ...
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HYDROGELS based on acrylamide and sodium acrylate have been prepared by the chemical initiation and gamma radiation methods. The chemical method was used in presence of ammonium persulfate at 30 oC, whereas, the gamma irradiation method was used in presence of triethanolamine at 1KGy. The complexed hydrogels were tested for the adsorption of metal ions, e.g. (Cu2+, Mn2+, Fe2+). Factors affecting metal ions adsorption by the gel namely, metal ion concentrations, and time of immersion were studied. The physical properties of the complexed gel namely U.V. -reflectance, X-ray diffraction, together with its thermal stability were studied. The scanning electron micrographs showed that the hydrogel has a great ability to adsorb metal ions in the following order Mn2+> Cu2+> Fe2+ . Release of metals from the complexed gel was investigated. Results showed that, the hydrogel prepared by gamma radiation has a greater tendency towards metal adsorption than the one prepared by chemical initiation.
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Antibacterial quinolones (QNs) are synthetic compounds with excellent complexation properties due to 4-oxo-1,4-dihydroquinolone structure with a 7-heterocycle containing nitrogen atoms. The metal complexes of these compounds had l...
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Antibacterial quinolones (QNs) are synthetic compounds with excellent complexation properties due to 4-oxo-1,4-dihydroquinolone structure with a 7-heterocycle containing nitrogen atoms. The metal complexes of these compounds had led to increased bacterial activity or other biological effects in comparison with the free ligand. Silver complexes with quinolone derivatives can offer a promising perspective through potential antibacterial, antiseptic, anti-inflammatory, and cytotoxic effects. In this review the obtaining methods of silver complexes with QNs are compared and discussed; in order to elucidate the chemical structure of reported silver complexes all reported information are reviewed and also the studied biological effects are highlighted and discussed. (C) 2017 Elsevier B.V. All rights reserved.
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Levofloxacin is a third generation fluoroquinolone antibiotic with a broad-spectrum including both Gram positive bacteria and Gram negative bacteria, as well atypical bacteria. In order to extend the spectrum of activity and to ad...
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Levofloxacin is a third generation fluoroquinolone antibiotic with a broad-spectrum including both Gram positive bacteria and Gram negative bacteria, as well atypical bacteria. In order to extend the spectrum of activity and to add new biological effects, several metal complexes of levofloxacin have been obtained and reported recently. The aim of our study was to obtain new silver complexes with levofloxacin with potential broad spectrum antibacterial and antifungal activity. Therefore three new silver complexes of levofloxacin with the proposed chemical structures (levofloxacin)(2)Ag(NO3), (levofloxacin)(2)Ag(NO3)(CH3OH) and (leyofloxacin)Ag(C6H6O7)center dot 3H(2)O were synthesized. In order to characterize the obtained complexes elemental analysis, conductivity measurement, spectroscopic, and thermal methods were used. Optimized molecular structures were determined using DFT (density functional theory) analysis. The antibacterial activity against Gram negative and Gram positive bacteria and antifungal activity against Candida spp of the complexes was tested by determination of minimum inhibitory concentration through microtitre broth dilution method. (C) 2016 Elsevier B.V. All rights reserved.
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Currently, polyolefin production is developing rapidly, and the demand for polyolefin in the world market is constantly increasing. Progress in this field is achieved by improvement of polymerization technology and development of ...
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Currently, polyolefin production is developing rapidly, and the demand for polyolefin in the world market is constantly increasing. Progress in this field is achieved by improvement of polymerization technology and development of highly active catalytic systems. Despite the highly developed processes, there is still a need to increase metallocene and postmetallocene catalytic systems productivity and efficiency required to carry out (co)polymerization processes of olefins, including ethylene. In most cases, the use of additives, modifiers, tandem and mixed systems and various substrates is a topical issue to reduce environmental pollution and increase efficiency of these processes. Despite the advances in metal complex polymerization of olefins, there's always a need to develop simple, environmentally and economically viable catalytic systems for obtaining the highest quality products. The article deals with the development of new titanium-and zirconium arylamine complex catalytic systems and their use in combination with metallocenes in ethylene polymerization with octene-1. It was determined in the studies, that the synthesized arylamine complexes have a simple method of preparation. These complexes with cocatalysts (methylaluminumoxane, diethylaluminum chloride, etc.) can be easily used both in ethylene polymerization and copolymerization with olefins. The products obtained in the presence of these catalytic systems were analyzed by various physico-chemical methods. It has been shown that high-density polyethylene is obtained in their presence. Copolymer obtained by the use of octene-1 in copolymerization process has a more branched structure. The metal complexes were characterized by modern HyperChem and Gaussian programs. The possibilities of adjusting the structure and composition of the products obtained in these catalytic systems were studied
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A calculating apparatus has been developed to help evaluate the stress-strain state in the plastic forming processes accompanied by a complex loading in which the Bauschinger effect can be manifested. The developed methods are bas...
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A calculating apparatus has been developed to help evaluate the stress-strain state in the plastic forming processes accompanied by a complex loading in which the Bauschinger effect can be manifested. The developed methods are based on the phenomenological approach in which a material map is devised in the form of flow curves, Bauschinger curves, a function j characterizing the hereditary influence of the loading history, plasticity diagrams, and limiting strain surfaces. To evaluate the plasticity resource used, taking into account the non-monotonicity of loading, the relations for determining the main components of the guiding strain-rate tensor were obtained, which made it possible to simplify the calculation of the components of the damage tensor. With the help of the developed calculating apparatus, the applied plasticity resource was evaluated in the process of radial extrusion with the contour sag, which allowed setting the limiting parameters of the shaping. Also, as a result of the research, an increase in the plasticity of the metal was established by selecting rational loading paths in the space of the dimensionless coordinates h, ms, and eu. For example, in the process of radial extrusion with the contour sag due to a change in the nature of the deformation, it was possible to obtain a flange diameter of 44 mm, with the initial diameter of the cylindrical workpiece being 20 mm. The results obtained are important because in most cases the processes of metal pressure treatment are accompanied by non-monotonic deformation.
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This dataset contains 82 unique refractory alloys experimentally synthesized via arc melting and subject to screening tests for hardness and room temperature ductility. Most compositions fall under the definition of high entropy o...
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This dataset contains 82 unique refractory alloys experimentally synthesized via arc melting and subject to screening tests for hardness and room temperature ductility. Most compositions fall under the definition of high entropy or complex concentrated alloys, but simpler ternary compositions are also included. Hardness was collected via a standard indentation technique while compressive ductility was quantified using a custom high throughput experimental approach yielding a ductility ranking from 0 to 5. The unique ductility screening test was developed to provide directional information for alloy development at a low cost and rapid pace using conventional test equipment. Predicted solidus temperature for all alloys is also included based on thermodynamic modelling. The dataset should be of interest to those exploring the emerging class of refractory high entropy alloys and particularly useful where optimization is sought balancing strength, ductility, and high melting temperature.
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Development of printable conductive inks for applications in printable electronics by facile methods is important. Here, this study demonstrates a robust and facile one-pot approach for printable polymer@Ag nanospheres with well-d...
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Development of printable conductive inks for applications in printable electronics by facile methods is important. Here, this study demonstrates a robust and facile one-pot approach for printable polymer@Ag nanospheres with well-defined hollow morphology. The polymer@Ag nanospheres are fabricated through metal-complexation induced phase separation assisted by a functionalized graft copolymer consisting of an Ag-complexing stem chain and side chains for stabilization of the nanosphere. Enough length of the grafted chains is necessary to attain the formation of the hollow polymer@Ag nanosphere. Translucent thin layers with excellent conductivity can be obtained by spray-coating of the nanostructure dispersion on a glass substrate. Translucent grid patterns with excellent horizontal conductivity (8.5 × 10~5 S m~(-1)) on multiple substrates are also prepared by ink-jet printing without annealing.
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Recently,we observed that the enantiopure A form of the tributy-lammonium salt of the chiral anion tris[tetrachlorobenzene-l,2-bis(olato)]-phosphate,also named Trisphat,was able to induce an efficient resolution of a A,A racemic m...
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Recently,we observed that the enantiopure A form of the tributy-lammonium salt of the chiral anion tris[tetrachlorobenzene-l,2-bis(olato)]-phosphate,also named Trisphat,was able to induce an efficient resolution of a A,A racemic mixture of cis-[Ru(dmp)_2(NCCH_3)_2](PF_6)_2 (dmp=2,9-dimethyl-l,10-phenanthroline)due to the spontaneous and selective precipitation of the heterochiral pair [A-Ru(dmp)_2(CH_3CN)_2] [A-Trisphat]_2.We report here that the combination of such a stereoselective precipitation process and irradiation results in the quantitative conversion of the initial [Ru(dmp)_2(NCCH_3)_2]~(2+)racemate into only one of the two enantiomers.This is the first example in inorganic chemistry of an asymmetric transformation that leads to a chiral complex with no chiral ligand.Finally,three new racemic ruthenium bis(diimine)complexes,namely [Ru(dmp)_2(NCCH_3)Py](PF_6)_2 (Py=pyridine),[Ru(dmp)_2(l ,3-diaminopro-pane)](PF_6)_2,and [Ru(dmp)_2(ethylene-diamine)](PF_6)_2 were synthesized.For all of them,crystallization-induced asymmetric transformation proved to be an efficient way of obtaining the corresponding optically active chiral-at-metal complexes in high yields and with excellent stereoselectivities.
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