A Greener Approach for Synthesis of Quinoline-3-carboxylate Building Block and their Biological Screening

The analogs of nitrogen-based heterocycles occupy an exclusive position as a value of more than 75% of drugs approved by the FDA and currently available in the market are nitrogen-containing heterocyclic moieties. Among many N-containing heterocycles, quinolines have become important due to their variety of applications in medicinal, synthetic organic chemistry as well as in the field of industrial chemistry. Present work gives information about the green and clean synthesis using multicomponent reactions (MCRs) methods and L-proline and ammonium acetate as a catalyst for the synthesis of quinoline derivatives. Synthesized quinoline derivatives undergo spectroscopic analysis and their biological evaluation.

Physicochemical Properties of Organophilic Clay Developed Using Hexadecyltrimethylammonium Chloride (HDTMAC) Modifier

Aims: Ogwuta clay from Unwana in the South Eastern part of Nigeria was modified by ion exchange reaction using hexadecyltrimethylammonium chloride (HDTMAC). Study Design: This study was analyzed experimentally and instrumentally. Place and Duration of Study: This study was carried out at the Department of Pure and Industrial Chemistry, Faculty of Science, University of Port Harcourt, Nigeria. The sample collection, literature search, experiment, results and analysis lasted for one and half years. Methodology: Physicochemical and thermal properties of the clay were determined after modification using classical and spectroscopic techniques. A combination of the wet and dry method (X-ray Fluorescence) was used to determine the metal oxide composition. Other techniques included; Fourier Transform Infrared (FTIR), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and Thermogravimetry (TG). The Cation Exchange Capacity (CEC) was determined using the methylene blue method with a value of 16.4 meq/100g after modification. Results: The product was slightly acidic with pH 4.3. Silica (SiO2), alumina (Al2O3), Na+, and K+ were found to be 47.58 %, 18.99%, 2.27, and 0.23% respectively. The clay was limited in mineral impurities with 0.0% T4+, 0.41% Mg2+, and 0.11% Ca2+ but high in carbonaceous matter with loss on ignition (LOI) of 13.17%. A C-H asymmetric stretching was visible around the 2931.9 cm-1 region as revealed by the Fourier Transform Infra-Red analysis. The X-Ray Diffraction analysis of the modified clay showed a basal spacing of 8.121 Å. Also, the X-Ray Diffractogram revealed kaolinite as the major clay mineral with the presence of quartz and polygorskite. Conclusion: This study posits that the modified clay can be potentially suitable for the adsorptive removal of organic contaminants in aqueous and real life media.

Support–Activity Relationship in Heterogeneous Catalysis for Biomass Valorization and Fine-Chemicals Production

Heterogeneous catalysts are progressively expanding their field of application, from high-throughput reactions for traditional industrial chemistry with production volumes reaching millions of tons per year, a sector in which they are key players, to more niche applications for the production of fine chemicals. These novel applications require a progressive utilization reduction of fossil feedstocks, in favor of renewable ones. Biomasses are the most accessible source of organic precursors, having as advantage their low cost and even distribution across the globe. Unfortunately, they are intrinsically inhomogeneous in nature and their efficient exploitation requires novel catalysts. In this process, an accurate design of the active phase performing the reaction is important; nevertheless, we are often neglecting the importance of the support in guaranteeing stable performances and improving catalytic activity. This review has the goal of gathering and highlighting the cases in which the supports (either derived or not from biomass wastes) share the worth of performing the catalysis with the active phase, for those reactions involving the synthesis of fine chemicals starting from biomasses as feedstocks.

Macromolecular Design for Oxygen/Nitrogen Permselective Membranes—Top-Performing Polymers in 2020—

Oxygen/nitrogen permselective membranes play particularly important roles in fundamental scientific studies and in a number of applications in industrial chemistry, but have not yet fulfilled their full potential. Organic polymers are the main materials used for such membranes because of the possibility of using sophisticated techniques of precise molecular design and their ready processability for making thin and large self-supporting membranes. However, since the difference in the properties of oxygen and nitrogen gas molecules is quite small, for example, their kinetic diameters are 3.46 Å and 3.64 Å, respectively, the architectures of the membrane macromolecules should be designed precisely. It has been reported often that oxygen permeability (PO2) and oxygen permselectivity (α = PO2/PN2) have trade-off relationships for symmetric membranes made from pure polymers. Some empirical upper bound lines have been reported in (ln α − ln PO2) plots since Robeson reported an upper bound line in 1991 for the first time. The main purpose of this review is to discuss suitable macromolecular structures that produce excellent oxygen/nitrogen permselective membranes. For this purpose, we first searched extensively and intensively for papers which had reported α and PO2 values through symmetric dense membranes from pure polymers. Then, we examined the chemical structures of the polymers showing the top performances in (ln α − ln PO2) plots, using their aged performances. Furthermore, we also explored progress in the molecular design in this field by comparing the best polymers reported by 2013 and those subsequently found up to now (2020) because of the rapid outstanding growth in this period. Finally, we discussed how to improve α and PO2 simultaneously on the basis of reported results using not only symmetric membranes of pure organic polymers but also composite asymmetric membranes containing various additives.

Inquiry through Industrial Chemistry in Compulsory Secondary Education for the Achievement of the Development of the 21st Century Skills

At a key moment when education systems are moving towards the development of 21st-century skills at school, we propose to develop them with a series of enquiry activities connected to the real world on the subject of Chemistry in Compulsory Secondary Education. The four selected topics have practical aspects, as they are related to industrial chemistry, and are proposed in educational practice using the 5E model. The results obtained in a pilot test with 22 students show that the context created facilitates the development of 21st century competences. It is understood that this novel proposal can be successfully employed in other contexts.

A Friendly Complexing Agent for Spectrophotometric Determination of Total Iron

Iron, one of the most common metals in the environment, plays a fundamental role in many biological as well as biogeochemical processes, which determine its availability in different oxidation states. Its relevance in environmental and industrial chemistry, human physiology, and many other fields has made it necessary to develop and optimize analysis techniques for accurate determination. Spectrophotometric methods are the most frequently applied in the analytical determination of iron in real samples. Taking advantage of the fact that desferrioxamine B, a trihydroxamic acid used since the 1970s in chelation therapy for iron overload treatment, forms a single stable 1:1 complex with iron in whichever oxidation state it can be found, a smart spectrophotometric method for the analytical determination of iron concentration was developed. In particular, the full compliance with the Lambert-Beer law, the range of iron concentration, the influence of pH, and the interference of other metal ions have been taken into account. The proposed method was validated in terms of LoD, LoQ, linearity, precision, and trueness, and has been applied for total iron determination in natural water certified material and in biological reference materials such as control human urine and control serum.

Immobilization Potential of Cow Manure for Heavy Metal Remediation from Refuse Dump Soil

Aims: The present study investigated the effect of cow manure amendment on fractionation and availability of some heavy metals (Cd, Cu, Cr, Mn, Pb and Zn) in refuse dump soil. Study Design: A greenhouse study experiment was conducted to determine the uptake of the metals by Ricinus communis in dump soil treated with 0%, 5%, 10% and 20% cow manure. Place and Duration of Study: The study was carried out at the Department of Pure and Industrial Chemistry, Nnamdi Azikiwe University Awka, Anambra State, Nigeria, between May and October 2018. Methodology: Experimental pots were filled with 2.0kg refuse dump soil in a green house and treated with 5%, 10% and 20% of Cow manure in three replicates per treatment. The seeds of Ricinus communis were planted in each pot and analysed after 12 weeks of planting for heavy metals using AAS. Sequential extraction was carried out on the treated soil after the harvest with each extract further analysed for heavy metals using AAS. Results: Application of cow manure significantly (p ˂ 0.05) affected the redistribution and the mobility of the heavy metals in the dump soil; as the concentration of the amendment increased, heavy metals in the mobile fractions reduced. 20% amendment had the best immobilization effect as the mobility factor decreased with increasing manure amendment. The mobility factors at 20% amendment were 18.34%, 15.82%, 5.23%, 15.86%, 25.56% and 12.81% for Cd, Cr, Cu, Mn, Pb and Zn respectively with the general trend of metal forms given as: residual > bound to organic > bound to Fe-Mn oxide > bound to carbonate > exchangeable. Conclusion: Cow manure amendment of the dump soil decreased the availability of heavy metals for plant uptake; and the metal uptake generally decreased as percentage amendment increased. Cow manure is therefore a good immobilizing agent for remediation of Cd, Cr, Cu, Mn, Pb and Zn in polluted soils.

Waste Tire Pyrolysis Product: An Alternative to Petrochemical Feedstock

Aim: The amount of waste tire generated constantly in the modern society is on a rapid increase due to the world’s urbanization, industrialization and population increase. This research was conducted to recover useful products from waste tyre and harness the possibility of using these products as a petrochemical feedstock alternative. Study Design: Conventional pyrolysis was used to produce bio char, bio-oil and bio-gas Place and Duration of Study: The research was carried out in the department of Pure and Industrial Chemistry and Mechanical Engineering Nnamdi Azikiwe University between January 2020 and march 2020 Methodology: Waste tyre was pyrolyzed using a conventional pyrolysis over three different temperature 400,550 and 750oC. The yield of the oil and char was determined by weight measurement, while that of gas was determined by mass balancing. The oil produced was characterized using GC/MS (gas chromatography/mass spectrometry) Results: The percentage yield of char, oil and gas at 400oC, 550oC and 750oC respectively are 62, 24, 14; 48, 36.2, 15.8 and 42, 40, 18. The statistical analysis of yield gave a p-value of 0.785211 this showed that there is no significant change across the three samples statistically. The GC/MS analyses of the oil showed that the oil contains more than 35 compounds of which 6 accounted for more than 50% of the oil, these six include d-limonene with 12.83%, 1-2- benzene dicarboxylic acid with 10.48%, benzene, 1-ethyl-3methyl with 8.89%, benzene 1-methyl-3-(1-methylethyl) with 8.6%, benzene 1-ethenyl-4-methyl with 6.13% and hexadecenoic acid at 5.27%,while another six accounted for less than 5% of the oil, they includes (1-methylenebut-2-enyl)benzene with 0.89%, 1-methylbut-1,3-dienyl)benzene with 0.71%, naphthalene-2,7-dimethyl with 0.71%, quinoline with 0.96%, Spiro[4,5]dec-7-ene,1,8-dimethyl-4-(1-methylethenyl) with 0.74%, phenol 4-(1,1,3,3-tetramethylbutyl). Conclusion: The composition of tire derived oil are very important petrochemicals derivatives which can be separated or can be used as feedstocks for petrochemical industries.