Synthesis of Novel Bithiophene-Substituted Heterocycles Bearing Carbonitrile Groups

Symmetrical and unsymmetrical bithiophene-substituted heterocycles bearing carbonitriles including imidazo[1,2-a]pyridine, benzimidazole, and pyridine derivatives have been synthesized via different synthetic protocols. The bithiophene bis-imidazo[1,2-a]pyridine derivatives 3a,b were achieved in three steps starting from 2-acetyl-5-bromothiophene. Suzuki coupling reaction of 2a with 5-formylthiophen-2-ylboronic acid forms the formyl derivative 5, which by condensation with 3,4-diaminobenzonitrile in the presence of sodium bisulfite furnishes the unsymmetrical bithiophene derivative6. The bis-benzimidazole derivative 8 was obtained via hexabutylditin-mediated homocoupling of 5-bromothiophene-2-carboxaldehyde, while the benzimidazole derivatives 12a,b were prepared via the formyl derivatives 11a,b, a product of Velsmier formylation reaction of 10a,b. Two synthetic protocols for the aryl/hetaryl-2,2′-bithiophene derivative 14 have also been presented. In addition, the guanyl hydrazones of bithiophenes, 16 and 17, were prepared from bis(tri-n-butylstannyl)-2,2′-bithiophene through a Stille coupling reaction followed by a condensation step.     

Application of New Modified Poly(ethylene Oxide)-Block-Poly(propylene oxide)-Block-Poly(ethylene oxide) Copolymers as Demulsifier for Petroleum Crude Oil Emulsion

Water soluble nonionic amphiphilic block copolymers based on hydrophilic poly(ethylene glycol) (PEG) and hydrophobic poly(propylene glycol) (PPG) were prepared. Poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) copolymers, PEG-PPG-PEG, were prepared in the normal condition. The chemical composition and molecular weights of the prepared copolymers were determined from ¹H NMR and GPC techniques. The surface properties of the prepared surfactants were determined by measuring the surface tension at different temperatures. The prepared nonionic surfactants were evaluated as demulsifiers for water in crude-oil emulsions that were pronounced at different ratios of crude oil: water at 318 K and 333 K. The experimental results showed that the dehydration rate of the prepared demulsifiers reached 100% based on demulsifier chemical compositions and concentrations.     

Ultra Moisturizing Anti-Wrinkle Lotion Enriched with Tocotrienols

A stable palm-based anti-wrinkle lotion enriched with tocotrienols was successfully prepared. The stability of the product was due to the presence of liquid crystalline structure in the emulsion system. It helps in bringing the active to the dermis layer. Functionality active ingredients such as tocotrienols and anti-wrinkle were added in the formulation. A commercial plant extract was used to strengthen the collagen seated at the dermis layer. The product was formulated to pH 5.5 which is suitable for the skin. The mean droplet size is 10.2 µm with a monomodal distribution pattern which prevents agglomeration. This will decrease Brownian motion, thus prolonging its stability. Long-term acute moisturizing tests show a significant increase of between 24% and 17% hydration for five and six weeks respectively. The efficacy testing on 12 subjects confirmed a reduction in natural fine wrinkles on faces during aging or premature aging at ?7.6%.     

Hydrogen production by steam reforming of glycerol over Ni/Ce/Cu hydroxyapatite-supported catalysts

Hydroxyapatite-supported Ni-Ce-Cu catalysts were synthesised and tested to study their potential for use in the steam reforming of glycerol to produce hydrogen. The catalysts were prepared by the deposition-precipitation method with variable nickel, cerium, and copper loadings. The performance of the catalysts was evaluated in terms of hydrogen yield at 600°C in a tubular fixed-bed microreactor. All catalysts were characterised by the BET surface area, XRD, TPR, TEM, and FE-SEM techniques. The reaction time was 240 min in a fixed-bed reactor at 600°C and atmospheric pressure with a water-to-glycerol feed molar ratio of 8: 1. It was found that the Ni-Ce-Cu (3 mass %-7.5 mass %-7.5 mass %) hydroxyapatite-supported catalyst afforded the highest hydrogen yield (57.5 %), with a glycerol conversion rate of 97.3 %. The results indicate that Ni/Ce/Cu/hydroxyapatite has great potential as a catalyst for hydrogen production by steam reforming of glycerol.     

Modeling of absorption kinetics of poly(acrylamide) hydrogels crosslinked by EGDMA and PEGDMAs

In this study, acrylamide-based hydrogels are synthesized by free radical solution polymerization in aqueous solution using ethylene glycol dimethacrylate (EGDMA) and its derivative polyethylene glycol dimethacrylate (PEGDMA) with different molecular weights as crosslinkers in the solution medium. The Fourier transform infrared spectroscopy technique is used for the structural characterization of the hydrogels. Dynamic swelling tests are conducted on acrylamide-based hydrogels for the determination of the swelling characteristics with respect to different crosslinking concentrations at room temperature. The parameters of swelling kinetics and diffusion mechanisms of the hydrogels are calculated with the aid of the data obtained. Accordingly, PEGDMA and EGDMA absorption capacity is found to increase with increasing concentrations. The lowest and highest water absorption capacities in PEGDMA₈₁₀ and EGDMA crosslinked hydrogels are 22.73–48.39 and 10.15–16.02 g/g, respectively. Water intake of hydrogels crosslinked by EGDMA and PEGDMAs followed Fickian nature type diffusion except for PEGDM₈₁₀, which has a swelling exponent greater than 0.5 and so does not follow a Fickian type of diffusion. PEGDM₈₁₀ showed the fastest diffusion rate of between 5.87 × 10^?4 and 10.87 × 10^?4 cm² s^?1.     

氨三乙酸、缬氨酸、亮氨酸的三元过渡金属配合物：合成和生物学应用

以氨三乙酸HNTA2-为主要配体,缬氨酸(valine)或亮氨酸(leucine)为次要配体在微酸性介质中合成了Ni(Ⅱ),Cu(Ⅱ),and Zn(Ⅱ)的三元配合物。用元素分析、热分析、FTIR,UV-Vis分光光度法,磁性测量和质谱法表征了合成的三元配合物。结果表明,三元配合物可在金属(M):氨三乙酸(HNTA)∶缬氨酸(valine)或亮氨酸(leucine)=1∶1∶1时制得,其分子结构为[M(HNTA)(valine)(H2O)2].1.5H2O and[M(HNTA)(leucine)(H2O)2].1.5H2O(其中M=Ni(Ⅱ)or Cu(Ⅱ))和H2[Zn(NTA)(valine)(H2O)]H2O。标题三元过渡金属配合物为八面体对称构型。同时研究了该三元配合物对大肠杆菌,金黄色葡萄球菌,白色念珠菌,黄曲霉菌(菌株从开罗大学理学院微分析中心获得)的抗菌活性。根据推荐的知名方法用标准的抗菌和抗真菌剂进行体外测试(in vitro)以评估我们的新制备的配合物对细菌和真菌物种的生长抑制活性。     

Base mediated synthesis of α-aminated aroyl/acetylnaphthalenes through [4+2] annulations

We have developed a base promoted simple, efficient and alternative approach for the synthesis of 4-amino-3-aroyl//heteroaroyl/acetyl-2-methylsulfanyl-naphthalene-1-carbonitriles by reaction of easily accessible 3,3-bis(methylthio)-1-aryl/heteroaryl/acetylprop-2-en-1-one and 2-cyanomethyl-benzonitrile. Reaction of 1-(2-halo/methoxy-phenyl)-3,3-bis(methylthio)prop-2-en-1-one and 2-cyanomethyl-benzonitrile under basic conditions also afforded 6-(methylthio)-7-oxo-7,12-dihydrobenzo[c]acridine-5-carbonitrile along with usual product. Structure of the synthesized product has been confirmed by single X-ray crystallography.     

Phenylpropanoids from Tanacetum baltistanicum with Nematocidal and Insecticidal Activities

Chemistry of Natural Compounds - One new and seven known secondary metabolites 1–8 were isolated, and the nematocidal and insecticidal activities of major compounds from Tanacetum...     

Reactive sensing capability towards the working electrical and chemical conditions of poly (aniline –co–o-toluidine) copolymers

Conducting polymers are considered as reactive gels which can sense the working ambient through their unique electrochemical reaction. Copolymers of aniline with o-toluidine for three different monomer compositions were synthesized chemically and were characterized using FTIR and UV-Vis spectroscopy, SEM, TGA, and cyclic voltammetry. The electrochemical reactive sensing characteristics with respect to the electrical and chemical working conditions of the copolymers were verified and compared through Chronopotentiometric responses in aqueous solutions of HCl by changing the reaction variables: applied current and chemical environment (electrolyte concentration) at a fixed constant charge. The consumed electrical energy during the electrochemical reaction of the copolymers varies linearly with the driving current and follows a logarithmic dependence on the electrolyte concentration. The consumed electrical energy during the reaction was found to act as the sensing parameter. At the same experimental condition, the sensitivity was associated with the conductivity of the copolymers. The highly conducting composition gives the highest sensitivity. These experimental results were fitted with the theoretical equation.

     

An updated review of nanofluids in various heat transfer devices

Journal of Thermal Analysis and Calorimetry - The field of nanofluids has received interesting attention since the concept of dispersing nanoscaled particles into a fluid was first introduced in...