European Journal of Chemistry

The sulfonamide moiety is present among a variety of biologically significant compounds. A facile synthesis is necessary to produce a variety of sulfonamides with the potential to improve human health. Herein, we report a facile methodology for the synthesis of 4-methylbenzenesulfonamides, amenable to a broad range of nitrogen nucleophiles. Implementing a semi-miscible biphasic solvent system resulted in higher yields, decreased reaction times, and a simplified workup over preliminary methods. Additionally, the crystal structures of five novel sulfonamide compounds and two polymorphs, have been determined by X-ray diffraction. Results obtained through spectroscopic characterization support the successful formation of the desired 4-methylbenzenesulfonamides.

In this study, it was discovered for the first time that the BiOBr/Bi_3.84W_0.16O_6.24 catalyst can efficiently degrade sulfadiazine (SDZ). Multiple techniques, such as X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV-Vis diffuse reflection spectroscopy (DRS) were applied to research the structures, morphology and photocatalytic properties of as-prepared samples. In addition, the effect of different synthesis pH environment and initial SDZ solution pH on the catalyst degradation efficiency were discussed. The BiOBr/Bi_3.84W_0.16O_6.24 catalyst synthesized under the condition of pH = 7 exhibited excellent photocatalytic activity for photodegradation of SDZ of 91% within 120 min under simulated solar light irradiation. Also, the roles of the radical species have been studied, and the ·O₂^- and h⁺ were proved to dominate the photocatalytic process. Based on the experimental results, the photocatalytic mechanism was proposed.

Attempts have been made to synthesis titanium dioxide (TiO₂) nanoparticles using titanium (IV) complexes of Schiff base (TiOL) as a precursor where Schiff base ligand (L) act as a dibasic tetradentate one. TiO₂ nanoparticles were synthesized by the direct calcination of titanium complexes at 500 °C for 3 hours. The analytical tools such as FT-IR, XRD, EDS, and SEM provided evidences in favor of the formation of TiO₂ nanoparticles_. Antimicrobial study showed that all prepared TiO₂ nanoparticles have inhibition capacity on the growth against selected plant pathogenic fungi as well as some selected human pathogenic bacteria. Moreover, these TiO₂ nanoparticles have catalytic capacity for the remarkable degradation (54.0%) of organic dye (Mordent brown 48) as well as industrial dye solutions.

Synthesis of 3-(1-((benzoyloxy)imino)ethyl)-2H-chromen-2-ones (1-5) was accomplished and it was characterized experimentally using various analytical techniques. Computational studies have been carried out for all compounds 1-5 using B3LYP method with 6-311++G(d,p) basis set. The optimized structural features viz. bond lengths, bond angles, and dihedral angles are compared with their single-crystal X-ray diffraction results of compound 1 (Crystal data for C₁₈H₁₃NO₄ (M = 307.29 g/mol): Monoclinic, space group P2₁/c (no. 14), a = 11.399(5) Å, b = 5.876(5) Å, c = 21.859(5) Å, β = 91.060(5)°, V = 1463.9(14) ų, Z = 4, T = 293(2) K, μ(MoKα) = 0.100 mm^-1, Dcalc = 1.394 g/cm³, 13555 reflections measured (3.58° ≤ 2Θ ≤ 56.98°), 3669 unique (R_int = 0.0235) which were used in all calculations. The final R₁ was 0.0444 (>2sigma(I)) and wR₂ was 0.1506 (all data)), which are in good conformity with each other. Normal modes of vibrational frequencies of compounds 1-5 acquired from density-functional theory (DFT) method coincided with the experimental ones. The ¹H and ¹³C chemical shifts of compounds 1-5 have been calculated by GIAO method and the results have been compared with the experimental ones. The first-order hyperpolarizability and their related properties of the novel molecules 1-5 are calculated computationally. The other parameters like natural bond orbital, zero-point vibrational energy, E_HOMO, E_LUMO, heat capacity and entropy have also been discussed.

The title compound lies about a crystallographic inversion centre located at the terephthalate moiety. The two peri-benzoylnaphthalene units having atrope chirality are also situated centrosymmetrically. In the two peri-benzoylnaphthalene moieties, two benzoyl groups are substituted at 1 and 8 carbons of the naphthalene ring in anti-orientation. Then two absolute configurations of peri-benzoylnaphthalene moieties are consequently assigned as complementary to each other, i.e., one unit has R,R-configuration and the other S,S-one, respectively. The two benzoyl groups in peri-benzoylnaphthalene moiety and the terephthalate phenylene ring are non-coplanarly located against the naphthalene ring. The dihedral angles of each benzene ring of two benzoyl groups and terephthalate unit with the naphthalene ring are 73.73 and 75.96, and 71.79°. In molecular packing, several kinds of weak interactions are responsible to induce three-dimensional molecular network. Especially, the synergetic effect realized through the bidentate hydrogen acceptor function in bidirectional C-H···π non-classical hydrogen bonds by the terephthalate phenylene ring moiety plausibly plays the determining role.

A one-pot two-component reaction of 3-oxo-2-arylhydrazones with active methylene nitriles under high pressure in a Q-tube safe reactor was reported. Comparison between conventional and Q-tube safe reactor-assisted synthesis of organic compounds was done by comparing total reaction time and percentage yield. The results show that the compound 5-cyano-6-oxo-1,4-diphenyl-1,6-dihydro-pyridazine-3-carboxylic acid ethyl ester (3) was synthesized within 2 h in a yield of 97%. In addition, the pyrazolo[3,4-c]pyridines 5b and 5c were obtained in yields of 93 and 95% within 1 h reaction time, respectively. The obtained results suggest that Q-tube safe reactor-assisted syntheses were led to higher product yields within very short reaction times.

Complexes of Co(II), [Co(C₂₆H₂₄N₈O₂)]·(ClO₄)₂·(H₂O)₂ (1), and Cu(II), [Cu(C₂₆H₂₃N₈O₂)]·(ClO₄) (2), have been synthesized. The prepared two compounds were characterized by elemental analysis, infrared and their structures were determined by single-crystal X-ray diffraction. The compound 1 crystallizes in the triclinic space group P-1 with the following unit cell parameters: a = 8.880 (5) Å, b = 10.529 (5) Å, c = 18.430 (5) Å, α = 99.407 (5)°, β = 102.174 (5)°, γ = 100.652 (5)°, V = 1618.2 (13) ų, Z = 2, T = 293(2), μ(MoKα) = 0.77 mm^-1, Dcalc = 1.582 g/cm³, 16135 reflections measured (5.050° ≤ 2q ≤ 59.152°), 7648 unique, R_int = 0.034 which were used in all calculations. The final R₁ was 0.066 (I ≥ 2σ(I)) and wR₂ was 0.22 (all data). The compound 2 crystallizes in the monoclinic space group P2₁/c with the following unit cell parameters : a = 11.652 (5) Å, b = 16.540 (5) Å, c = 14.512 (5) Å, β = 93.495 (5)°, V = 2791.6 (18) ų, Z = 4, T = 293(2), μ(MoKα) = 1.05 mm^-1, Dcalc = 1.768 g/cm³, 15592 reflections measured (5.624° ≤ 2θ ≤ 58.804°), 6630 unique, R_int = 0.025 which were used in all calculations. The final R₁ was 0.050 (I ≥ 2σ(I)) and wR₂ was 0.144 (all data). In both complexes, the ligand acts in a tridentate fashion. In the structure of the mononuclear complex 1, the Co(II) cation is coordinated by two ligand molecules. The basal plane around the Co(II) cation is occupied by two pyridine nitrogen atoms and two carbonyl oxygen atoms. Two imino nitrogen atoms occupy the apical positions of the distorted square-pyramidal geometry. The mononuclear 2 consists of a Cu(II) coordinated by one ligand and one monodeprotonated ligand molecule. The metal center lies in a distorted square bipyramidal environment. The basal plane around the Cu(II) is occupied by two pyridine nitrogen atoms and two carbonyl oxygen atoms, the apical position being occupied by the two imino nitrogen atoms.

Assembly of small building blocks such as atoms, molecules, nanoparticles, and microparticles into macroscopic structures has opened up new and exciting opportunities in the realm of nanotechnology and microtechnology. Here, we report a simple hydrothermal approach for assembling chromic hydroxide microscopic particles into three-dimensional chromic hydroxide with cylindrical morphology. The morphology and size as prepared samples are controlled by the concentration of Cr(NO₃)₃. Our approach provides a reliable way to successfully assemble various other types of particles into cylindrical macrostructures, realizing the shape engineering of nanoscale and microscale structures to macroscopic well-defined architectures for further applications.

A sensitive, accurate, and precise liquid chromatographic method has been developed and validated for the determination of Linagliptin (LNG) and Empagliflozin (EMP) in their combined tablets. Chromatographic separation was carried out on ODS-3 Inertsil^® C18 column (150×4.6 mm, 5 µm). The mobile phase A (consisting of 0.30% Triethyl amine buffer (TEA) at pH = 4.5, adjusted using ortho-phosphoric acid); the mobile phase B (consisting of acetonitrile) was pumped through the column whose temperature was maintained at 40 °C, with a flow rate 1.7 mL/min, using gradient elution from 0-3 min A:B (75:25, v:v), then from 3-6 min the ratio changed to be A:B (60:40, v:v). Fluorescence detection (FLD) was performed at 410 nm after excitation at 239 nm. Acceptable linearity, accuracy and precision values of the proposed method were found over the concentration ranges of 0.5-15 µg/mL for LNG and 1.0-30 µg/mL for EMP with correlation coefficients of 0.9997 and 0.9998 in the case of LNG and EMP, respectively. The recoveries and relative standard deviations percentages were found in the following ranges: 98.56-101.85 and 0.53-1.52% for LNG and 98.00-101.95 and 0.31-1.05% for EMP. The detection and quantification limits were 0.15 and 0.45 µg/mL for LNG and 0.22 and 0.67 µg/mL for EMP. The optimized method was validated and proved to be specific, robust, accurate and reliable for the determination of the drugs in pure form or in their combined pharmaceutical preparations. No significant difference was found regarding accuracy and precision upon statistical comparison between the obtained results of the proposed method and those of the reported method. Furthermore, the proposed method is proved to be a stability-indicating assay after exposure of the studied drugs to variable forced degradation parameters, such as acidic, alkaline and oxidative conditions, according to the recommendations of the International Conference on Harmonization guidelines. The simplicity and selectivity of the proposed method allows its use in quality control laboratories.

The crystals of an unprecedented 2,4,5-tri(N-methylpyridinium)-1,3-thiazole are monoclinic and belong to the space group P2₁/c as determined by single-crystal XRD. Crystal data for C₂₁H₂₁I₁₃N₄S_5.98: monoclinic, a = 7.5627(5) Å, b = 30.6764(19) Å, c = 20.8848(15) Å, β = 91.632(6)°, V = 4843.2(6) Å³, Z = 4, T = 100.01(10) K, μ(Cu Kα) = 67.840 mm^-1, Dcalc = 2.977 g/cm³, 17906 reflections measured (7.152° ≤ 2Θ ≤ 162.94°), 17906 unique (R_sigma = 0.0607) which were used in all calculations. The final R₁ was 0.1366 (I > 2σ(I)) and wR₂ was 0.3926 (all data). The crystal lattice contains 2,4,5-tri(N-methylpyridinium)-1,3-thiazole, molecular iodine and triiodide counterions which interact with one another to coordinatively form polyiodides, as well as a surprising co-crystallized neutral molecule of cyclododecasulfur (S₁₂). Close monitoring of the synthetic procedure reveals chemical condensation and decomposition of the thioamide reagent to be the impetus for the formation of individual components of the crystal lattice. Analysis of the XRD, including a Hirshfeld surface analysis, shows that (a) the crystal lattice has a number of stabilizing Coulombic short contacts such as I∙∙∙I, I∙∙∙S, I∙∙∙C, and C∙∙∙S and non-classical C-H∙∙∙I and C-H∙∙∙S hydrogen bond interactions (b) the iodine/iodide network are major determinants in the stability of its crystal lattice despite the reduced occupancies of sulfur and (c) the Hirshfeld analysis in comparison with the conventional Mercury visualization program was able to simplify, identify and quantify complex atom-atom interactions such as H∙∙∙H and N∙∙∙I in its crystal lattice. Herein, it is reported, for the first time, the formation of co-crystallized, neutral cyclododecasulfur (S₁₂) from thioamide as the sulfur source. S₁₂ displays a consistent geometry and comparable average S-S distances, S-S-S angles and torsion angles with previously reported crystal structures of S₁₂. The complex network facilitated by the formation of polyiodides via the interaction of symmetric and asymmetric triiodides and iodine has resulted in quite strong interactions that are less than the sums of the van der Waals radii of two connected atoms as well as an array of fascinating geometrical alignments such as T-shape, trigonal pyramidal and L-shape.

An analog of spirooxindole[pyrano-bis-2H-l-benzopyran] derivatives namely 5-bromospiro [indoline-3,7'-pyrano[3,2-c:5,6-c']dichromene]-2,6',8'-trione was synthesized via one-pot pseudo three-component reaction of one equivalent of 5-bromoisatin and two equivalents of 4-hydroxycoumarin using mandelic acid as a naturally occurring organo catalyst in aqueous ethanol under reflux conditions. The synthesized compound was characterized by FT-IR, ¹H NMR, ¹³C NMR, and HRMS data. Crystal structure was determined by using single X-ray crystallography technique. It was found that the crystals are triclinic with space group P-1, C₁₀₈H₆₀Br₄N₄O₂₉S₂: a = 11.8333(6) Å, b = 12.8151(6) Å, c = 17.1798(8) Å, α = 77.317(4)°, β = 74.147(4)°, γ = 66.493(5)°, V = 2280.0(2) Å³, Z = 1, T = 149.99(10) K, μ(MoKα) = 1.902 mm^-1, Dcalc = 1.647 g/cm³, 11545 reflections measured (3.836° ≤ 2Θ ≤ 50.998°), 8310 unique (R_int = 0.0488, R_sigma = 0.0875) which were used in all calculations. The final R₁ was 0.0622 (I > 2σ(I)) and wR₂ was 0.1994 (all data). The crystal structure was solved by direct methods and refined by full-matrix least-squares procedure to a final R-value of 0.0622 for 6264 observed reflections. The crystal structure was stabilized by an elaborate system of N-H···O, O-H···O, C-H···π, and π···π interactions involving solvent molecules to form supramolecular structure.

Fluoroquinolones are a family of broad spectrum, systemic antibacterial agents that have been used as therapy for infections in the respiratory and alimentary tract in animals. The pharmacodynamic of this class is widely described, predominantly to the commercial drugs ciprofloxacin (CIP), enrofloxacin (ENR), and pefloxacin (PEF). Bovine serum albumin (BSA) is the main endogenous carrier in the bovine bloodstream, being responsible for the biodistribution of different classes of molecules and drugs, including fluoroquinolones. The molecular features and interaction between BSA and fluoroquinolones are not fully described, thus, the present work enlightens the intimacy of the interaction of BSA with CIP, ENR, PEF through structural modeling and molecular docking calculation approaches. The role of key amino acid residues was assessed, indicating that the main protein binding pocket is composed by Trp-212 residue playing an important stabilization for the three fluoroquinolones through both hydrogen bonding and van der Waals forces, where reside the individual structural differences observed among the three fluoroquinolones and BSA. There is a descriptive protagonism of carboxyl group on the ENR interaction which traps the molecule and avoids the deep communication in the protein binding pocket, as well as the ligands CIP and PEF showed an interface amino acid residue interaction profile higher than 70%.

The crystal structure of La₂Mg_17-xSn_x solid solution was determined by single crystal X-ray diffraction for the first time. This phase crystallizes in hexagonal symmetry with space group P6₃/mmc (a = 10.3911(3), c = 10.2702(3) Å, V = 960.36(6) ų, R₁ = 0.0180, wR₂ = 0.0443 for the composition La_3.65Mg₃₀Sn_1.10) and is related to the structure of CeMg_10.3 and Th₂Ni₁₇-types which are derivative from the CaCu₅-type. A series of isotypical solid solutions La₂Mg_17-xM_x (M = Ni, Sn, Sb, x ~0.8) was synthesized and studied by X-ray powder diffraction, energy dispersive X-ray spectroscopy and fluorescent X-ray spectroscopy. All solid solutions crystallize with the structure related to the Th₂Ni₁₇-type. The electrochemical hydrogenation confirmed the similar electrochemical behavior of all studied alloys. The amount of deintercalated hydrogen depends on the physical and chemical characteristics of doping elements and increases in the sequence Sn < Mg < Sb < Ni. The most geometrically advantageous sites are octahedral voids 6h of the initial structure, thus a coordination polyhedron for H-atom is an octahedron [HLa₂(Mg,M)₄].

Three Schiff bases 1-(4-chlorophenyl)-N-(naphthalen-1-yl)methanimine (1), 1-(4-methoxy phenyl)-N-(naphthalen-1-yl)methanimine (2), and 1-(4-chlorophenyl)-N-(2,6-diisopropyl phenyl)methanimine (3) were synthesized and characterized by elemental analysis, ¹H and ¹³C NMR, FT-IR and UV-Visible spectroscopic techniques. The crystal structure of compound 3 was obtained and it revealed that the compound crystallized in a monoclinic space group P2₁/n and there exists an intermolecular hydrogen bond in a phenyl-imine form with C-H⋯N. Crystal data for C₁₉H₂₂ClN: a = 7.28280(10) Å, b = 9.94270(10) Å, c = 24.0413(2) Å, β = 97.0120(10)°, V = 1727.83(3) Å³, Z = 4, μ(Mo Kα) = 0.215 mm^-1, Dcalc = 1.1526 g/cm³, 14038 reflections measured (12.42° ≤ 2Θ ≤ 52.74°), 3448 unique (R_int = 0.0223, R_sigma = 0.0182) which were used in all calculations. The final R₁ was 0.0337 (I≥2u(I)) and wR₂ was 0.0927 (all data). The free radical scavenging activities of all three compounds were assayed using DPPH, FRAP, and OH assays. According to results obtained, compound 2 shows effective DPPH^- (IC₅₀ = 22.69±0.14 μg/mL), FRAP⁺ (IC₅₀ = 28.44±0.12 μg/mL), and OH^- (IC₅₀ = 27.97±0.16 μg/mL) scavenging activities compared with compounds 1 and 3 but less than standard antioxidant compound Trolox (TRO). Additionally, theoretical calculations for the three complexes were performed by using density functional theory (DFT) calculations at the B3LYP/6-31++G(2d,2p) level in the ground state to obtain an optimized geometrical structure and to perform an electronic, molecular electronic potential surface and natural bond orbital (NBO) analysis. The geometrical calculation obtained was found to be consistent with the experimental geometry. Further analysis was conducted using the in silico technique to predict the drug likeness, molecular and ADME properties of these molecules.

New Ti(IV), Zr(IV) and Al(III) salen-based complexes of formulae [(L)TiCl₂], 2, [(L)ZrCl₂], 3, and [(L){Al(CH₂CH(CH₃)₂)₂}₂], 4, where L = meso-(R,S)-diphenylethylene-salen, were synthesized in high yields. [(L){Al(CH₂CH(CH₃)₂)₂}₂] is a bimetallic complex that results from the reaction of H₂L with either 1 or 2 equivalent of Al(CH₂CH(CH₃)₂)₃. The solid-state molecular structures of compounds 2 and 4·(C₇H₈) were obtained by single-crystal X-ray diffraction. Crystal data for C₄₄H₅₄Cl₂N₂O₂Ti, (2a): monoclinic, space group C2/c (no. 15), a = 27.384(1) Å, b = 12.1436(8) Å, c = 28.773(2) Å, β = 112.644(2)°, V = 8830.6(9) ų, Z = 8, μ(MoKα) = 0.350 mm^-1, Dcalc = 1.146 g/cm³, 26647 reflections measured (5.204° ≤ 2Θ ≤ 50.7°), 8072 unique (R_int = 0.0967, R_sigma = 0.1241) which were used in all calculations. The final R₁ was 0.0640 (I > 2σ(I)) and wR₂ was 0.1907 (all data). Crystal data for C₆₂H₇₂Cl₂N₂O₂Ti (2b): monoclinic, space group P2₁/c (no. 14), a = 19.606(1) Å, b = 12.793(1) Å, c = 23.189(2) Å, β = 105.710(4)°, V = 5599.0(7) ų, Z = 4, μ(MoKα) = 0.291 mm^-1, Dcalc = 1.182 g/cm³, 37593 reflections measured (3.65° ≤ 2Θ ≤ 50.928°), 10304 unique (R_int = 0.0866, R_sigma = 0.1032) which were used in all calculations. The final R₁ was 0.0593 (I > 2σ(I)) and wR₂ was 0.1501 (all data). Crystal data for C₆₇H₉₇Al₂N₂O₂ (4·(C₇H₈)): triclinic, space group P-1 (no. 2), a = 10.0619(9) Å, b = 16.612(2) Å, c = 21.308(2) Å, α = 67.193(5)°, β = 78.157(6)°, γ = 77.576(5)°, V = 3176.8(6) ų, Z = 2, μ(MoKα) = 0.088 mm^-1, Dcalc = 1.063 g/cm³, 42107 reflections measured (5.382° ≤ 2Θ ≤ 51.624°), 12111 unique (R_int = 0.0624, R_sigma = 0.0706) which were used in all calculations. The final R₁ was 0.0568 (I > 2σ(I)) and wR₂ was 0.1611 (all data). The solid-state molecular structure of [(L){Al(CH₂CH(CH₃)₂)₂}₂] reveals that both metal centres display a slightly distorted tetrahedral geometry bridged by the salen ligand. Both [(L)TiCl₂] and [(L)ZrCl₂] complexes display octahedral geometry with trans-chlorido ligands.

The novel coronavirus, which emerged in China in late December 2019, is officially named as Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). The rapid spread of the virus across the continent has disrupted human life in every aspect leading to health and economic crises. The World Health Organization (WHO) declared the novel coronavirus outbreak as a global pandemic on March 11, 2020. In spite of complete lockdown and quarantine efforts in many countries, the occurrence of infections continues to rise, with more than 88 million laboratory-confirmed cases and over 1.9 million deaths worldwide as on January 10, 2021. Since the beginning of the outbreak, lot of intriguing studies about the phylogenetic evolution, epidemiology, pathogenesis, transmission, clinical characteristics, and possible treatment of Corona Virus Disease 2019 (COVID-19) have been published. This review aims to provide an insight into the progress in this regard and provides a reference for future studies including general awareness. We have discussed the origin, transmission, and infection mechanism of coronaviruses in host cells as well as available treatment options with relevant case studies. Furthermore, the stages of vaccine development, types of vaccines, and candidate vaccines with their phases of clinical trial are also incorporated. In a nutshell, the article is an attempt to retrieve the latest information available on virus behavior, efficacy of the available drugs, and development of candidate vaccines on SARS-CoV-2.