European Journal of Chemistry
ISSN / EISSN : 2153-2249 / 2153-2257
Published by: European Journal of Chemistry (10.5155)
Total articles ≅ 970
Latest articles in this journal
European Journal of Chemistry, Volume 12, pp 304-313; https://doi.org/10.5155/eurjchem.12.3.304-313.2099
The compound 2-(4-fluorophenoxy) acetic acid was synthesized by refluxing, 4-fluoro-phenol as a starting material with ethyl chloroacetate in acetone as solvent. The compound crystallizes in the monoclinic crystal system with the space group P21/c. Crystal data for C8H7FO3, a = 13.3087(17) Å, b = 4.9912(6) Å, c = 11.6018(15) Å, β = 104.171(4)°, V = 747.21(16) Å3, Z = 4, T = 293(2) K, μ(CuKα) = 1.142 mm-1, Dcalc = 1.512 g/cm3, 8759 reflections measured (13.72° ≤ 2Θ ≤ 130.62°), 1246 unique (Rint = 0.0528) which were used in all calculations. The final R1 was 0.0458 (>2sigma(I)) and wR2 was 0.1313 (all data). The structure was stabilized by C-H···O and C-H···Cg interactions. The intermolecular interactions in the crystal were studied using Hirshfeld surface analysis. 3D energy frameworks were computed to visualize the packing modes. DFT calculations were performed. The FMOs were studied to estimate the kinetic stability and reactivity of the molecule. The MEP surface was generated to investigate the charge distribution and chemical reactive sites in the molecule.
European Journal of Chemistry, Volume 12, pp 323-328; https://doi.org/10.5155/eurjchem.12.3.323-328.2134
This study reports an organic salt prepared from an antibacterial drug, levofloxacin and antioxidant γ-resorcylic acid. A simple preparation method leads to a crystal with disordered structure. The idea is to prepare an organic salt comprising of pharmaceutically acceptable acidic and basic components. The salt is characterised by IR, solid state NMR, and single crystal XRD. Crystal data for C25H26N3O8F: triclinic, space group P-1 (no. 2), a = 7.0037(8) Å, b = 12.764(3) Å, c = 13.909(3) Å, α = 104.821(4)°, β = 92.039(4)°, γ = 95.334(4)°, V = 1194.6(4) Å3, Z = 2, T = 296(2) K, μ(MoKα) = 0.113 mm-1, Dcalc = 1.433 g/cm3, 16879 reflections measured (5.048° ≤ 2Θ ≤ 54.186°), 5139 unique (Rint = 0.0663, Rsigma = 0.0975) which were used in all calculations. The final R1 was 0.1121 (I>2σ(I)) and wR2 was 0.2505 (all data). SC-XRD analysis shows that the crystal packing is stabilized by strong H-bonding of type N-H···O and comparatively weak interactions of type C-H···O, C-H···π and off-set π···π stacking.
European Journal of Chemistry, Volume 12, pp 360-360; https://doi.org/10.5155/eurjchem.12.3.360-360.2178
Retraction notice to “The chemistry of group-VIb metal carbonyls” [Eur. J. Chem. 2012, 3(3), 367-394, doi: 10.5155/eurjchem.3.3.367-394.604]
European Journal of Chemistry, Volume 12, pp 340-359; https://doi.org/10.5155/eurjchem.12.3.340-359.2126
Considering the highly important biological and medicinal properties of naphthofurans, the synthesis of these heterocycles has attracted the interest of medicinal and organic chemists. This review aims to describe the different strategies developed so far for the synthesis of naphthofurans and their applications and the literature reports for the period of 2000 to early 2020. After a brief introduction of the types of naphthofurans and their biological activities, the different synthetic approaches such as chemical and photochemical, methods are described and organized on the basis of the catalysts and the other reagents employed in the syntheses. Some of the reactions have been applied successfully to the synthesis of biologically important compounds.
European Journal of Chemistry, Volume 12, pp 242-247; https://doi.org/10.5155/eurjchem.12.3.242-247.2085
Promoting the green technology campaign that would actualize a biorefinery establishment and would promote cleaner fuel production and air in our environment. This study carried out kinetics studies of biodiesel production over a mixed oxide, Ca-Mg-O catalyst, providing relevant kinetics parameters. This study indicated that biodiesel production is a zero-order reaction, a process independent of the concentration. The results obtained from this study confirm the activation energy, Ea, of the reaction to be 406.53 J/mol, while the pre-exponential factor A was found to be 0.01618 1/min (or 0.9 1/h). Other are kinetics models that were developed for the prediction of the reaction kinetics for the production process is also reported in this study. The findings reported in this study would go a long way to facilitate the modeling, simulation, and design of the biodiesel production process.
European Journal of Chemistry, Volume 12; https://doi.org/10.5155/eurjchem.12.3.iii-vi.2180
European Journal of Chemistry, Volume 12; https://doi.org/10.5155/eurjchem.12.3.i-ii.2179
European Journal of Chemistry, Volume 12, pp 289-298; https://doi.org/10.5155/eurjchem.12.3.289-298.2127
Caffeine is a refractory pollutant of emerging concern that evades conventional waste-water treatment techniques. Here, we report the synthesis of visible light responsive perovskite structured LaMnO3 photocatalyst using modified Pechini method and utilized it as an efficient photocatalyst for caffeine degradation. XRD, BET, UV-Vis, NH3-TPD, and SEM were used to characterize the photocatalyst. Response surface methodology using Central composite design was used to investigate the effect of three operational variables; catalyst dosage, initial caffeine concentration and pH on the caffeine photocatalytic degradation efficiency. The functional relationship between these operational variables and caffeine photocatalytic degradation efficiency was established be a second order polynomial model. The results of the response surface analysis indicate caffeine degradation efficiency is most significantly affected by catalyst dosage and pH. The optimal values of operational obtained by response surface optimization were found be 3.5 g/L for catalyst dosage, 7.9 and 44.6 mg/L for pH and initial caffeine concentration respectively given the caffeine degradation efficiency of 93.9%.
European Journal of Chemistry, Volume 12, pp 273-278; https://doi.org/10.5155/eurjchem.12.3.273-278.2120
Caking formation in fertilizer products during handling and storage is a frequently encountered problem. Caked fertilizers become together as lumps, lose their free- flowing properties, and create inefficient applications. Several parameters such as relative humidity and temperature of the environment, pressure by pile height, and physicochemical properties of fertilizer product such as moisture content, presence of fines and chemical composition, etc. cause or accelerate caking mechanism. Internal or external anticaking products have been proved to be effective in preventing the caking of fertilizer particles. Liquid or wax anticaking agents are applied externally as coatings on the fertilizer surface. This study focuses on the performance evaluation of commercially available liquid- wax anticaking agents coated on NP 20-20-0 fertilizer, classified as three main groups: petroleum-derived, alkyl amine-fatty acid containing mixtures and bio- based composition. Caking performance of coating products are evaluated via small-bag storage test in 4 sets, according to the results, petroleum derived and alkyl amine- fatty acid containing anticaking products show similar performance, whereas bio-based products’ performance is moderate. This study focuses on a practical approach that will help fertilizer industry about which type of coating product will be effective on the anticaking properties of nitrogenous fertilizers and gives brief results of the effect of commercially available products with various ranges of chemical composition on the caking process.
European Journal of Chemistry, Volume 12, pp 284-288; https://doi.org/10.5155/eurjchem.12.3.284-288.2131
Caffeine is naturally present in tea and coffee giving the pleasant and stimulant effect. Several different types of teas, black, green, and white teas bought in market were analysis for caffeine content. The boiled sample tea was filtered through filter paper. Lead(II) acetate was used to separate tannins from caffeine followed by filtration through filter paper with a black ribbon. The liquid-liquid extraction was carried out using dichloromethane (3×5 mL) and sodium sulfate as a drying agent. The TLC method was performed on Merck precoated silica gel plates 5×10 cm (60F254, 200 μm) using either methanol or dichloromethane as solvents and the mobile phases were glacial acetic acid and ethyl acetate (95:5, v/v), while the second one was consisted of ethyl acetate and ethanol (80:20, v/v), respectfully. The Rf values were 0.36 and 0.86 for the first and the second mobile phase, respectively, in comparison to the standard caffeine. The values for pH of boiled sample teas were in the range from 4.85 to 5.80. The most abundant tea sample for caffeine was determined in green tea bought in the grocery store for health nutrition (2.04 %). The yield for tea samples from green market, white tea and two tea black samples were 0.06, 0.71, 0.07, and 0.05%, respectively. The developed TLC method can be used for determination of caffeine content in tea samples.