European Journal of Chemistry

A new spectrofluorimetric reagent N-(pyridin-2-yl)-quinoline-2-carbothioamide (PQTA) has been synthesized and characterized. A very simple, ultra-sensitive, and highly selective, and non-extractive new spectrofluorimetric method for the determination of molybdenum at pico-trace levels using PQTA has been developed. This novel fluorimetric reagent PQTA, becomes oxidized in a slightly acidic (0.0025-0.05 M H₂SO₄) solution with molybdenum (VI) in absolute ethanol to produce a highly fluorescent oxidized product (λ_ex = 300 nm; λ_em= 377 nm). Constant and maximum fluorescence intensities were observed over a wide range of acidity (0.0025-0.0500 M H₂SO₄) for the period between 2 min and 24 h. Linear calibration graphs were obtained for 0.001-600 μg/L of Mo having a detection limit of 0.15 ng/L; the quantification limit of the reaction system was found to be 1.5 ng/L and the RSD was 0-2%. A large excess of over 60 cations, anions, and complexing agents like chloride, phosphate, azide, tartrate, oxalate, and SCN^- etc. do not interfere in the determination. The developed method was successfully used in the determination of molybdenum in several Certified Reference Materials (Alloys, steel, serum, bovine liver, drinking water, soil, and sediments) as well as in some environmental waters (Potable and polluted), biological fluids (Human blood, urine, hair, and milk), soil samples and food samples (Vegetables, rice, and wheat) solutions containing both molybdenum (VI) and molybdenum (V) ions. The results of the proposed method for assessing biological, food and vegetable samples were comparable with ICP-OES and AAS were found to be in excellent agreement.

The development of highly effective and low-toxicity nonsteroidal anti-inflammatory drugs (NSAIDs) is one of the important challenges facing modern pharmacology. To overcome this problem, many studies have been conducted on compounds containing a five-membered heterocycle containing three nitrogen atoms. The pharmacodynamics of these compounds are mainly due to their anti-inflammatory effect. Therefore, it is important to synthesize new derivatives of 1,2,3-triazoles, to determine their structure and to look for substances with anti-inflammatory activity on their basis. For the first time, the corresponding derivatives of 4-(4-(exchangeable)-1H-1,2,3-triazole-1-yl)-benzoic acid were synthesized by cycloaddition of propargyl esters of saturated carboxylic acids and para-azidobenzoic acid in the presence of copper (I) iodide. The structure of the obtained substances was analyzed by IR, ¹H NMR, and MS techniques. It is proved that under the action of the catalyst in the reaction, only 1,4-isomers are formed. Factors affecting the course of the reaction were identified. Only one isomer is formed in the reaction of cyclic addition under the action of a catalyst and the effect of temperature, duration of time, and nature of the solvent on the reaction yield was studied.

A rapid UPLC-ESI-MS method was developed for simultaneous determination of caffeine and taurine in beverages (energy drinks and soft drinks). The molecular ions of caffeine and taurine were identified in single ion recording mode at m/z 194.98 and 125.86, respectively. The mass spectrometer parameters were optimized as: capillary voltage 3.0 kV, cone voltage 35 V, extractor 3 V, RF Lens 0.1 V, source temperature 150 °C, desolvation temperature 350 °C, nitrogen 600 L/h, LMR1 7.9, HMR1 15.2, IE1 0.30. The mobile phase comprising methanol (0.1% formic acid) (A) and water (5 mM ammonium acetate) (B) was used in gradient mode. The mobile phase components A and B were pumped in 80:20 (v:v) ratio from 0-0.44 min, and then 100% of component A was pumped between 0.45-0.68 min, and at 0.69 min the composition was returned to 80:20 (v:v) ratio of A and B till 2.0 min. Caffeine and taurine were eluted at 0.46 and 0.43 min, respectively. The samples of energy drinks and soft drinks were diluted in a solvent system comprising methanol and water in 80:20 (v:v) ratio. Our investigations showed that soft drinks SD1 and SD2 have 88.8±4.2% and 110.7±3.6% (w:w) caffeine of their labeled claim. The caffeine content in energy drink brands ED1, ED2, ED3, and ED4 was 76.9±2.5, 65.6±3.4, 88.1±12.6, and 89.1±2.8% (w:w) of labeled claims, respectively. While taurine content in ED1, ED2, ED3, and ED4 was 86.5±8.4, 81.3±27.5, 101.9±4.8, and 97.1±0.3% (w:w) of labeled claim, respectively.

Three organophosphorus mercury (II) coordination compounds [Hg₂(µ-X)₂X₂(PPh₃)₂] {X: I (1), Br (2), and Cl (3)} have been synthesized by the reaction of mercury (II) halides with triphenylphosphine. The prepared complexes were characterized by spectroscopic techniques as well as by elemental analysis. The crystal structure of [Hg₂(µ-I)₂I₂(PPh₃)₂] (1) was obtained by single-crystal X-ray diffraction study. Crystal data for [Hg₂(µ-I)₂I₂(PPh₃)₂], C₃₆H₃₀Hg₂I₄P₂: Monoclinic, space group P2₁/c (no. 14), a = 19.2115(13) Å, b = 11.1291(8) Å, c = 19.0599(14) Å, β = 90.461(2)°, V = 4075.0(5) Å³, Z = 4, T = 293.15 K, μ (MoKα) = 10.657 mm^-1, Dcalc = 2.336 g/cm³, 46095 reflections measured (4.23° ≤ 2Θ ≤ 49.994°), 7182 unique (R_int = 0.0563, R_sigma = 0.0365) which were used in all calculations. The final R₁ was 0.0322 (I > 2σ(I)) and wR₂ was 0.0780 (all data). The single crystal analysis of [Hg₂(µ-I)₂I₂(PPh₃)₂] complex revealed that it has dimeric structure with bridged halides. [Hg₂(µ-I)₂I₂(PPh₃)₂] complex has also a supramolecular arrangement through I···H-C interactions. The crystal packing and supramolecular features of these coordination compounds have also been studied using geometrical analysis, Hirshfeld surface analysis and DFT studies. Hirshfeld surface analysis indicated that H···H (49.3%), C···H (10.6%), and I···H (12.8%) interactions are the primary contributors to the intermolecular stabilization in the crystal. The equilibrium geometries of the studied complexes are investigated theoretically at the B3LYP/LANL2DZ level of theory. The calculated energy gap between HOMO-LUMO orbitals for complexes 1, 2, and 3 are in the trend of complex 3 > 2 > 1.

Senegal is affected by a relatively high prevalence of iodine deficiency disorders, which compromises its social and economic development. To address this situation, the Universal Salt Iodization strategy was adopted by the Senegalese Government. The monitoring of salt iodine status is crucial to the success of such a program. Therefore, this study aimed to evaluate the iodine concentration of table salt from Senegalese households. A total of 1575 samples collected in urban and rural areas were analyzed using the iodometric method. The powdered salt samples showed higher mean iodine content (18.99 ppm) and lower percentage of non-compliance (58.4%) than the other salt types (p = 0.02). Most of the samples collected from urban area were found with iodine content between 15 and 39.9 ppm, whereas, in rural areas, the situation was significantly different (p = 0.01). Iodine levels of most samples were lower than 5 ppm in the rural producing area or varied between 5 to 14.9 ppm in the rural non-producing area. A percentage of 37.3% of adequately iodized salt samples was obtained at a national scale with a significant disparity between urban and rural areas. Therefore, improvements in quality control procedures in tandem with the iodization process are necessary and an information, education and communication strategy should be adopted.

The synthesis, antimicrobial, and antioxidant activities of new quinoline analogs were carried out with the aim to find possible hits/leads that can be taken up for future drug development. A series of 2-amino-N’-((2-chloroquinolin-3-yl)methylene)acetohydrazide derivatives (6a-h) have been synthesized by reacting 2-chloro-N’-((2-chloroquinolin-3-yl)methylene)acetohydrazide (5a) and N’-((6-bromo-2-chloroquinolin-3-yl)methylene)-2-chloroacetohydrazide (5b) with secondary amines (Morpholine, diethylamine, piperidine and 1-methylpiperazine). The characterization was achieved by FT-IR, ¹H NMR, ¹³C NMR, and mass spectral analysis. The in silico ADMET studies of the synthesized molecules were analyzed for their drug likeliness and toxic properties. The ADMET study indicates that the synthesized compounds were found to be possessing reliable ADME properties and are nontoxic. The antimicrobial properties were tested against bacterial and fungal species with amoxicillin and fluconazole as standard drugs. The compounds 6a, 6c, 6e, and 6g exhibited good antibacterial potency against P. aeruginosa, and the compounds 6a, 6f, and 6h have shown good activity against E. coli with 1000 µg/mL. The compounds 6b, 6c, and 6e have moderate activity against fungal species C. oxysporum and the compounds 6c, 6e, 6f, 6g, and 6h have good activity against P. chrysogenum. Synthesized compounds were also tested for the DPPH· free radical scavenging activity to check the antioxidant potential, and the results revealed that the compounds 6a, 6b, 6c, and 6e have exhibited antioxidant potency than the remaining synthesized derivatives. The possible hits generated from biological activity could be taken for the generation of lead molecules for the drug discovery of antimicrobial and antioxidant entities from quinoline.

Metal-organic frameworks (MOFs)/coordination polymers (CPs) are a new class of hybrid inorganic/organic porous material. Recently MOFs have attracted much attention due to their large surface area, tunable pore structure, and high thermal stability. MOF-5 is composed of zinc salt and 1,4 benzene dicarboxylic linker. In the current study, MOF-5/cryogel composite was applied to extract cholesterol selectively from milk samples. This extraction process was used to clean-up milk samples with MOF-5/cryogel composite followed by determination of cholesterol in milk using UV-Vis spectrophotometric technique. The parameters such as concentration of cholesterol, volume of cholesterol solution, adsorbent amount, adsorption and desorption time were studied to obtain good extraction of cholesterol. The amount of cholesterol adsorbed and desorbed was 84 and 80%, respectively, from milk samples using MOF-5 composite cryogel. The developed method was validated in terms of linearity, accuracy, precision, limit of detection, and quantification. The response was linear in the range of 5-200 µg/mL with a coefficient of determination (r²) of 0.990. Detection limit (0.15 µg/mL) and quantification (0.45 µg/mL) were obtained.

Since street drugs are frequently and rapidly modified, in order to circumvent the current laws that make them illicit, it is necessary to fully identify them by single crystal X-ray diffraction; subsequently, ideal powder patterns are computed for rapid identification of additional confiscations, which are mostly available in powder form. Monoacetyl morphine is found in samples of heroin as a by-product of incomplete synthesis, or from degradation of diacetyl morphine caused by heat, humidity, or pH changes. It is formed by the hydrolysis of the acetyl function on the benzene moiety of the morphine ring, thereby inserting an OH moiety at that site. This compound, 6-monoacetyl morphine, is the primary and active metabolite of heroin, rapidly hydrolyzed in the user’s blood. Herein, we describe the structure of 6-monoacetyl morphine, IUPAC name: [(4R,4aR,7S,7aR,12bS)-9-hydroxy-3-methyl-2,4,4a,7,7a,13-hexahydro-1H-4,12-methanobenzofuro[3,2-e]isoquinolin-7-yl] acetate (A), as the trihydrated hydrochloride, whose structure has not been described previously. Our crystals belong in space group P2₁2₁2₁ with cell parameters of a = 6.9367(2), b = 13.0374(3), c = 21.9856(6) Å, V = 1988.30 (9) ų; its composition is C₁₉H₂₂NO₄Cl·3H₂O, and Z = 4.0. A full sphere of data was collected at 100 K using CuKα radiation (λ = 1.54178 Å), yielding 3594 unique reflections measured and a final R-factor = 4.1%, with a Flack parameter = 0.05(1).

Schiff bases are versatile ligands, synthesized via condensation of primary amines with carbonyl compounds. In this study, equimolar amounts of 4-imidazolecarboxaldehyde and thiosemicarbazide were combined and the Schiff base 4-imidazolecarboxaldehyde thiosemicarbazone was prepared as a new bidentate complexing agent. The synthesized ligand was reacted with palladium (II) and platinum (II) ions yielding air-stable complexes. For characterization purpose, infrared spectra, mass spectra, electronic spectra, thermal analysis, proton nuclear magnetic resonance and 13-carbon nuclear magnetic resonance spectra studies were carried out on the obtained complexes and ligand. The characterization data showed that the ligand acts as a bidentate coordinate to the metal ions through azomethine nitrogen and sulfur atoms. An in vitro antimicrobial investigation was also carried out for the free ligand and its metal complexes against four bacteria; Bacillus cereus, Staphylococcus aureus (Gram-positive), Escherichia coli and Salmonella typhimurium (Gram-negative) and one Fungi; Candida albicans, to assess their antimicrobial properties by disc diffusion technique. Antimicrobial activity of the prepared complexes showed higher activity than the free ligand.

The synthetic leucite silicate framework mineral analogues Cs₂XSi₅O₁₂ (X = Cu, Cd, Zn) were prepared by high-temperature solid-state synthesis. The results of Rietveld refinement, using 18 keV synchrotron X-ray powder diffraction data collected at low temperatures (8K X = Cu, Zn; 10K X = Cd) show that the title compounds crystallize in the space group Pbca and are isostructural with the ambient temperature structures of these analogues. The structures consist of tetrahedrally coordinated SiO₄ and XO₄ sharing corners to form a partially substituted silicate framework. Extraframework Cs cations sit in channels in the framework. All atoms occupy the 8c general position for this space group. In these refined structures, silicon and X atoms are ordered onto separate tetrahedrally coordinated sites (T-sites).

This study aimed to use microwave irradiation as a green technique, not only to enhance the dyeing efficiency of disperse-colored polyester fabrics, but also to conserve resources and minimize the environmental effects. Arylazopyrazolopyrimidinones dyes 1-9 were applied to polyester fabrics at 2% shade using conventional method and microwave at 100 °C. Both the color intensity expressed as dye absorption and the fastness characteristics of the dyed fabric were investigated. The K/S values are increased by increasing the time of irradiation from 10-60 minutes. The dyed substrate displayed good light fastness, and very good fastness levels to rubbing, perspiration washing, and sublimation, respectively.

Chalcones are the main component of some natural compounds. The title compound, 3-(2,5-dimethoxyphenyl)-1-(naphthalen-2-yl)prop-2-en-1-one, was synthesized and characterized. The compound (C₂₁H₁₈O₃) crystallizes in the triclinic system with the space group of P-1 (no. 2), a = 7.7705(4) Å, b = 10.2634(6) Å, c = 11.2487(6) Å, α = 79.655(5)°, β = 81.500(5)°, γ = 68.039(5)°, V = 815.28(9) Å³, Z = 2, T = 293(2) K, μ(MoKα) = 0.086 mm^-1, Dcalc = 1.297 g/cm³, 9126 reflections measured (4.318° ≤ 2Θ ≤ 52.728°), 3302 unique (R_int = 0.0466, R_sigma = 0.0528) which were used in all calculations. The final R₁ was 0.0568 (I > 2σ(I)) and wR₂ was 0.1667 (all data). The crystal structure is stabilized by both short C-H···O inter- and intra-molecular interactions. In addition, the crystal structure is reinforced by π-π interactions. Hirshfeld surface analysis confirmed the presence of C-H···O intermolecular interactions. The two-dimensional fingerprint plots are used to visualize the individual interactions present in the molecule. DFT calculations were performed to know the energy levels of the frontier molecular orbitals (HOMO-LUMO). The energy gap between the frontier molecular orbitals shows the kinetic stability of the molecule. The chemical reactive sites are observed by generating MEP surface. Non-covalent interactions (NCIs) are analyzed using reduced density gradient (RDG) analysis.

Several studies have reported the presence of amine and imine tautomeric forms for hydrogenated 1,3-thiazine derivatives. However, identification of their tautomeric forms by UV, FTIR and mass-spectral methods does not yield expected results. Here, we report the synthesis of 2-phenylaminodihydro-1,3-thiazine and 2-phenyliminotetrahydro-1,3-thiazine and the analysis of their UV, FTIR and NMR (¹H and ¹³C) spectral data. An identical picture of UV spectra was recorded for both compounds. However, distinctive characteristics were found in the FTIR, ¹H and ¹³C NMR spectra. The C=N band of amine form was observed in higher frequency region relative to imine form. The signal of C2 carbon of amine form in ¹³C NMR spectrum was occurred in more downfield (δ 165.3 ppm) relative to C2 signal of imine form (δ 152.1 ppm). In addition, the difference between C2 and C8 carbon signals of amine form was very high (Δδ = 30.6 ppm) relative to imine form (δ 5.4 ppm). The position of C2 and C8 signals and the difference between them in ¹³C NMR spectrum was found to be more promising in identification of tautomeric forms in case of hydrogenated 1,3-thiazine derivatives.

The crystal structure of the sesquihydrate of dehydroepiandrosterone propan-2-ylidene hydrazone, [(7)₂·(H₂O)₃], isolated from a solution of dehydroepiandrosterone propan-2-ylidene hydrazone, (7), in moist ethanol at room temperature, has been determined from data collected at 100 K. The sesquihydrate recrystallizes in the orthorhombic space group, P2₁2₁2₁ with Z = 8. The asymmetric unit of [(7)₂·(H₂O)₃] consists of two independent molecules of the steroid, Mol A and Mol B, and three moles of water. The six membered saturated rings, A and C, in both molecules have ideal or near ideal chair shapes, the unsaturated rings, B, have the expected half-chair shapes, while the five-membered rings, D, have envelope shapes with flaps at C114 and C214 for Mol A and Mol B, respectively. Differences in the conformations of the two molecules reside essentially completely within the hydrazonyl fragments with significantly different torsional angles, C117-N120-N121-C122 (in Mol A) and C217-N220-N221-C222 (in Mol B), of 149.19(14) and -93.08(17)°, respectively. The difference in this torsional angle is reflected in the hydrogen bonds involving the nitrogen atoms in the hydrazonyl units: it is of interest that the hydrazonyl nitrogen atoms partake as acceptors in hydrogen bonding with water molecules. The only intermolecular interactions in these molecules are hydrogen bonds -all classical O-H-O and OH···N hydrogen bonds with just one exception, a C-H···O_(water) hydrogen bond. Of interest, there are no direct steroid-steroid links: molecules are linked solely by hydrogen bonds involving the hydrate molecules. All three hydrate molecules take part in the indirect linking of the steroid molecules, but each has its own set of contacts.

Currently, the size and shape selective synthesis of nanoparticles (NPs) and their varied catalytic applications are gaining significant enthusiasm in the field of nanochemistry. Homogeneous catalysis is crucial due to its inherent benefits like high selectivity and mild reaction conditions. Nevertheless, it endures with serious disadvantages of catalysts and/or product separation/recycles compared to their heterogeneous counterparts restricting their catalytic applications. The utilization of catalysts in the form of nano-size is an elective methodology for the combination of merits of homogeneous and heterogeneous catalysis. Magnesium oxide (MgO) NPs are important as they find applications for catalysis, organic transformation, and synthesis of fine chemicals and organic intermediates. The applications of MgO NPs in diverse organic transformations including oxidation, reduction, epoxidation, condensation, and C-C, C-N, C-O, C-S bond formation in a variety of notable heterocyclic reactions are also discussed. The use of MgO NPs in organic transformation is advantageous as it mitigates the use of ligands; the procurable separation of catalyst for recyclability makes the protocol heterogeneous and monetary. MgO NPs gave efficacious catalytic performance towards the desired products due to high surface area. By considering these efficient merits, scientists have focused their attentions towards stupendous applications of MgO NPs in selective organic transformation. In the current review article, we summarized the synthesis of MgO NPs and numerous characterization techniques, whereas the application section illustrates their utility as a catalyst in several organic transformations. We believe this decisive appraisal will provide imperative details to further advance the application of MgO NPs in selective catalysis.