European Journal of Chemistry

According to recent research on the application of graphene materials as sensors and particularly polypyrrole-graphene materials, which are especially promising, the functionalization of graphene with a pyrrole molecule might be considered a viable alternative as a NO₂ and NH₃ sensor. In this way, a graphene sheet simulated as a coronene molecule was used in order to test whether this kind of functionalization could be useful for detecting the NO₂ and NH₃ toxic gases with a relatively high sensitivity. NO₂ was studied as an example of an electron acceptor molecule, and NH₃ as an electron donor molecule. Both molecules were adsorbed on two different regions of the functionalized adsorbent, and the energy ranges found for adsorption were reported and compared with those of the pristine graphene. The results indicated that in the coronene-pyrrole system, pyrrole tends to lie almost parallel to the coronene sheet in a π-π stacking interaction between the two conjugated systems, being the closest distances of 3.0 and 3.2 Å. The use of Δ (Δ_HOMO-LUMO) as a descriptor confirmed that the coronene-pyrrole system is a good option as a NO₂- and NH₃-sensor; therefore, it might be an easy and suitable descriptor for characterizing the performance of a sensor; all calculations were made using a Density Functional formalism, through a functional M06-2X in combination with the 6-31G(d,p) basis set.

Kinetic Monte Carlo modeling was employed to investigate the kinetics and photodecomposition mechanism of sulfamethazine, ciprofloxacin, sulfathiazole, and amoxicillin antibiotics by the photo-Fenton process (iron(III) citrate/hydrogen peroxide in the presence of UV irradiation). The reaction kinetic mechanisms of each photo-Fenton degradation mentioned above have been achieved. The rate constants values for each step of the reaction mechanisms (including photo-Fenton process of antibiotics) were obtained as adjustable parameters by kinetic Monte Carlo simulation. The optimized values of iron(III) citrate and hydrogen peroxide were investigated through the obtaining the effect of their initial amounts on the rate of antibiotic elimination utilizing kinetic Monte Carlo simulation. The perfect agreement is observed between the simulation results and the experimental photo-Fenton data for the systems above.

In this paper, we report the synthesis and characterization of the dioxidovanadium(V) complex derived from a malonohydrazide ligand (N'¹,N'³-bis(2-hydroxybenzylidene) malonohydrazide). The newly synthesized complex was characterized by infrared spectroscopy (IR), nuclear magnetic resonance (NMR), and the structure of the complex was also established by a single crystal X-ray diffraction study. The bimetallic complex crystallizes in the triclinic space group P-1 with the following parameters a = 10.8273(5) Å, b = 11.4677(6) Å, c = 15.0366(8) Å, α = 81.591(4)°, β = 83.018(4)°, γ = 76.326(4)°, V = 1787.23(16) Å³, Z = 2, T = 292.5(2) K, μ(MoKα) = 0.600 mm^-1, Dcalc = 1.463 g/cm³, 11730 reflections measured (6.236° ≤ 2Θ ≤ 58.062°), 7981 unique (R_int = 0.0231, R_sigma = 0.0506) which were used in all calculations. The final R₁ was 0.0496 (I > 2σ(I)) and wR₂ was 0.1255 (all data). The ligand was coordinated to the metal ions in a tridentate fashion through the donor O/N/O atoms. The metal ions adopted a square pyramidal geometry with slight distortion. Reaction of the complex with hydrogen peroxide was also carried out, and it was found that the complex reacts with hydrogen peroxide to form a peroxo complex.

A new binuclear copper (II) complex [Cu₂L₂Cl₄(H₂O)₂] (1) derived from 4,4',6,6'-tetramethyl-2,2'-bipyrimidine (L) has been synthesized and characterized by the single crystal X-ray diffraction method. Single crystal analysis of complex 1 reveals that it crystallizes in the space group P2₁/n under a monoclinic system (β = 97.995(2)°, a = 7.6483(2), b = 7.2158(3) and c = 17.8477(6) Å). The ligand acts as a bis-bidentate one and each copper (II) center bears a square pyramidal geometry exploiting N₂Cl₂O chromophore. In the solid state, the complex is stabilized through classical O-H···Cl intermolecular hydrogen bonding incorporating coordinated water (as a solvent) and chloride ions and lone pair···π interactions. The Hirshfeld surface analysis demonstrates H···H/H···H, H···Cl/Cl···H, H···C/C···H, and C···Cl/Cl···C intermolecular interactions as the major contributor interactions in the solid-state packing of the molecular crystal. Interaction energy calculations carried out employing the wavefunction generated via B3LYP/6-31G(d,p) highlight the dominance of electrostatic energy and the contribution of polarization and dispersion energy towards the total energy of complex 1 in the solid state.

The main objective of this study was to examine the quality of water in the large reservoir of the Dhaka city lake and to determine whether it would be economically acceptable to purify this water for later use and to make it usable. The water quality parameters investigated are pH, temperature, electrical conductivity, hardness, alkalinity, total dissolved solids, total suspended solids, chloride, sulfate, phosphate, nitrite, nitrate, biochemical oxygen demand, chemical oxygen demand, and dissolved oxygen. The study has been done targeting three specific locations on Dhanmondi Lake, where crowds are comparatively the highest. This implies that there is a significant likelihood of pollution as well. The results of our 13-month study show that the quality of Dhanmondi lake water is somewhat higher than the international standard and some is at a tolerable level determined by the Bangladesh Department of Environment.

Osteoporosis is a bone disease caused due to the reducing bone mineral density. Porous and more fragile bones increase the risk of fractures. Hip, spine, shoulder, and wrist bones are commonly affected by osteoporosis. Low bone density is a leading cause of osteoporosis. The most efficient prescribed drugs for the treatment of osteoporosis are bisphosphonates drugs. Alendronate was the first FDA approved bisphosphonate drug for the treatment of osteoporosis. Osteoclast cells are the primary targeting site for alendronate, responsible for bone resorption. A biopharmaceutical classification system class III bisphosphonate acts as a potent, efficient, and bone resorption inhibitor drug. In the present study, alendronate functionalized PLGA based nanoparticles were developed by a solvent diffusion method and optimized for different process variables. The formulated nanoparticles were characterized for surface morphology, particle size distribution, surface charge and drug-polymer compatibility. The scanning electron microscopy and transmission electron microscopy results showed nanoparticle size in the range below 200 nm. The average particle size and zeta potential of the formulated nanoparticles were found to be 175.3 nm and -13.98 mV, respectively. The highest encapsulation efficiency was 65.23%. The release profile was dissolution medium dependent and followed by the Higuchi model of release kinetics.

A new heterocyclic hydrazone Schiff base ligand, N'-(4-(diethylamino)-2-hydroxy benzylidene)-4-oxopiperidine-1-carbohydrazide, (H₂L) was derived by a condensation reaction of 4-oxopiperidine-1-carbohydrazide with 4-(diethylamino)-2-hydroxybenz-aldehyde. The ligand reacts with chloride salts of chromium(III), manganese(II), iron(III), cobalt(II), nickel(II), copper(II) and zinc(II) to form metal complexes of [Cr(L)(Cl)(H₂O)₂], [Mn(HL)(Cl)(H₂O)₂], [Fe(L)(Cl)(H₂O)₂], [Co(HL)(Cl)(H₂O)₂], [Ni(HL)(Cl)(H₂O)₂], [Cu(HL)(Cl) (H₂O)₂], [Zn(L)(H₂O)], respectively. The structure of the hydrazone ligand was confirmed by elemental analysis and spectroscopic techniques, viz., FT-IR, ¹H NMR, ¹³C NMR, and LC-MS spectroscopy. The newly synthesized ligand behaves as a tridentate ONO donor towards Cr, Mn, Fe, Co, Ni, Cu, and Zn metal ions. The spectral, magnetic moment, and thermal data indicate the octahedral geometry for all metal complexes except for Zn, which has tetrahedral geometry with 1:1 stoichiometry (M:L). ESR study revealed that π-bonding covalency is much stronger than the σ-bonding with axial distortion in the structure. The molar conductivity data suggested the nonelectrolytic nature of the complexes. The powder X-ray diffraction patterns suggest the nanocrystalline nature of the compounds. The SEM micrograph of the ligand significantly differs from its Ni(II) complex indicating coordination of Ni(II) ion to the ligand. The intense fluorescence emitted in the region of λ_Excitation 521 to 524 nm due to the functional fluorophores of the ligand and its manganese (II), chromium(III), cobalt(II), and zinc(II) complexes. Various kinetic parameters such as E_a, ∆S, ∆H, and ∆G of various decomposition steps were calculated from TGA diagrams using Coats-Redfern method and the thermal stability order was found to be Cr < Fe < Co < Mn = Cu < Zn < Ni. The antibacterial and antifungal activities of the ligand and its divalent and trivalent metal complexes were performed against the various pathogens viz. Escherichia coli, Salmonella typhi, Staphylococcus aureus, Bacillus subtilis, Candida albicans, and Aspergillus niger with reference to standard antibiotics viz. ofloxacin, azithromycin, and fluconazole. All metal complexes showed promising biological activity as compared with their parent ligand and may be used as a potential antimicrobial candidate in biological science.

N'-Arylidene-2-((7-methylbenzo[4, 5]thiazolo[2,3-c][1, 2, 4]triazol-3-yl)thio)acetohydrazides (6a-j) were prepared by condensation of 2-((7-methylbenzo[4,5]thiazolo[2,3-c][1,2,4] triazol-3-yl)thio)acetohydrazide with appropriately substituted benzaldehydes in dry methanol and a catalytic amount of glacial acetic acid. The prepared compounds tested for in vitro Type II diabetes inhibition and antimicrobial (antibacterial and antifungal) activities employing α-amylase inhibition assay and the serial dilution method, respectively. Type II diabetes inhibitory assay results of all the tested derivatives revealed that precursor 3 (IC₅₀ = 0.16 μM) and acetohydrazide 6i (IC₅₀ = 0.38 μM) showed comparable activity with standard drug acarbose (IC₅₀ = 0.15 μM). The derivatives 6i against B. subtilis and E. coli with MIC values of 0.0300 μmol/mL, compound 6c against S. aureus (MIC = 0.0312 μmol/mL) and compound 6e against P. aeruginosa (MIC = 0.0316 μmol/mL) exhibited remarkable antibacterial activity, however, compound 6b was found to be more active against the fungal strain C. albicans with MIC value of 0.0135 μmol/mL. All acetohydrazides (6a-j) showed greater potency against all strains tested than their precursors 1-4, which is also supported by the results of molecular docking analysis. Furthermore, no general trend for structure activity relationships was established for Type II diabetes inhibitory activity, nor antimicrobial activities of the tested hydrazones (6a-j).

The pure phase crystals of Michler’s ketone, [4-(CH₃)₂NC₆H₄]₂CO, are reported herein as monoclinic in the space group P2₁/c with Z’ = 2 by single-crystal X-ray diffraction. The data collection of the title compound proved quite difficult, which could explain why the structure has not been reported previously. The crystallographically independent molecules in the asymmetric unit differ by dihedral angles of 24.60/30.34° and 25.25/27.20° between the essentially planar 4-dimethylaminophenyl (DMAP) rings and the central C₂C=O plane of the ketone and dihedral angles of 52.14 and 47.41°, respectively, between the DMAP planes. A DMAP ring of each molecule overlaps in the lattice with a methyl ring that overlays the ring centroid of the opposite number (C_Me-C_g distances of 3.452 and 3.505 Å), describing sets of trifurcated C_Ar-acceptor hydrogen bond interactions (HBIs). The trifurcated HBIs possess H∙∙∙C_Ar distances of 2.90, 2.75, and 2.86 Å; C_Me∙∙∙C_ar distances of 3.554(5), 3.798(5) and 3.881(5) Å; and ÐC_Me-H∙∙∙C_Ar of 115.0, 121.3 and 167.7°, respectively. Stabilization of the asymmetric unit in the title compound is further achieved by supramolecular synthons such as C_Me-H∙∙∙C_Ar (2.831 Å), C_Ar-H∙∙∙O (2.561 Å) and C_Ar-H∙∙∙H-C_Ar (2.290 Å) and coulombic C_Me-Ocontact (3.209 Å). The structures of the two independent molecules in the asymmetric unit of the title compound were compared with the same molecule as found in the following co-crystals, adducts or salts: a halogen-bonded adduct with 1,4-diiodotetrafluorobenzene; a hydrogen-bonded adduct with a fluorinated phenol; a coordination complex between the ketone and a trimeric mercury acceptor; and two salts from protonation or methylation at one of the amino nitrogen atoms.

In this work, N-(2-methoxy-benzyl)-acetamide (2MBA) was synthesized from an amide derivative and it was characterized by FT-IR and NMR spectroscopy techniques. The crystal structure of 2MBA was also validated via single-crystal X-ray diffraction analysis. Crystal data for C₁₀H₁₃NO₂ for 2MBA: Monoclinic, space group P2₁/n (no. 14), a = 9.1264(6) Å, b = 9.3375(7) Å, c = 11.9385(8) Å, β = 95.745(5)°, V = 1012.26(12) Å³, Z = 4, μ(MoKα) = 0.082 mm^-1, Dcalc = 1.176 g/cm³, 5632 reflections measured (5.368° ≤ 2Θ ≤ 51.992°), 1990 unique (R_int = 0.0377, R_sigma = 0.0314) which were used in all calculations. The final R₁ was 0.0583 (I > 2σ(I)) and wR₂ was 0.1444 (all data).  The intermolecular interactions in 2MBA were theoretically examined by Hirshfeld surface analysis and 2D fingerprint plots. Moreover, the HOMO and LUMO energy gaps of 2MBA was calculated by DFT calculation with the B3LYP/6-311G++(d,p) method. The electron-withdrawing and donating sites of the 2MBA were confirmed via molecular electrostatic potential surface analysis. The present study discusses the title compound not only highlighted the crystallographic data but also revealed good molecular interactions together with an anticancer drug target, which is a targeting PARP protein, which was an important drug target in the treatment of breast cancer.

The biosorption of hexavalent chromium ions from aqueous solution was investigated using acid-modified dead biomass of the abundantly available brown marine alga Cystoseira indica from Karachi coastal area of Pakistan. The biosorbent was characterized by infrared spectroscopy and scanning electron microscopy. The optimum biosorption conditions, i.e., biosorbent dosage, contact time, initial metal ion concentration, pH, and temperature, were determined by carrying out batch-mode experiments. The sorption behavior was established by the Langmuir and Freundlich isotherms, which showed that although the uptake of metals was more feasible on a heterogeneous surface, homogeneous surface conditions seemed to exist at the same time. The thermodynamic parameters ∆G°, ∆H° and ∆S° calculated at different temperatures ranging from 298 to 318 K demonstrated that the biosorption was a spontaneous and exothermic process under the experimental conditions applied.

Packaging materials based on biodegradable polymers are a viable alternative to replacing conventional plastic packaging of fossil origin. The main two factors affecting functionality and performance are the molecular weight and the type of plasticizer used in these materials. The goal of this research was to modify unfractionated plasticized chitosan films to improve the physical and mechanical characteristics of the original unfractionated chitosan films. Chitosan extracted from local shrimp shells was zone-refined to produce five distinct chitosan fractions with molecular weights ranging from 1.089×10⁵ to 5.605×10⁵ g/mole. The unfractionated and fractionated chitosan films plasticized with 1:3 poly(vinyl alcohol) and 2:1 maleic acid were prepared by casting from their 2% acetic acid solutions. They were examined by FT-IR and were found to be comparable to the native chitosan spectrum, indicating that the primary backbone of the chitosan structure was unaltered. Therefore, the effects of molecular weight fractions and the type of plasticizer on the physical and mechanical properties were investigated. Examining the films’ surface topography by atomic force microscopy revealed that increasing the molecular weight of chitosan fractions from 2.702×10⁵ to 5.605×10⁵ g/mole affects the surface morphology of the chitosan: poly(vinyl alcohol) (1:3) film. This was accompanied by an increase in the surface roughness of the resulting film from 0.953 to 2.82, and for chitosan: maleic acid from 0.509 to 1.62. It was found that the tensile strength and Young’s modulus of the cast films decreased and the percent elongation at break of the plasticized fractionated chitosan films was increased, implying that less stiff films were obtained with fractionated chitosan. The outcome of this work suggests that the biodegradable fractionated chitosan blend film is a promising packaging material and that poly(vinyl alcohol) is the most suitable plasticizer for this formulation.

A crystal of organic salt, 2,4,6-trimethylpyridinium picrate (TMPPc), was synthesized and magnified by slow evaporation in a polar aprotic solvent and characterized by ¹H NMR, ¹³C NMR, and FT-IR spectroscopic methods. X-ray diffraction analysis of the crystal structure of the compound TMPPc showed the presence of a monoclinic space group with a = 4.0174(4) Å, b = 27.863(3) Å, c = 13.9247(17) Å, β = 95.741(4)°, V = 1550.9(3) Å³, Z = 4, T = 296 K, μ(MoKα) = 0.123 mm^-1, Dcalc = 1.500 g/cm³, 62749 reflections measured (5.88° ≤ 2Θ ≤ 57.058°), 3911 unique (R_int = 0.0536, R_sigma = 0.0226) which were used in all calculations. The final R₁ was 0.0569 (I > 2σ(I)) and wR₂ was 0.1710 (all data). Detailed investigation of molecular packing of the TMPPc molecule indicated the presence of intermolecular hydrogen bond between N4-H44···O1 and C13-H13B···O4 that generates C₂²(14) chain running parallel to the [001] direction. The infrared and Raman spectra of the prepared TMPPc compound were recorded and discussed. The thermal stability of the obtained TMPPc crystal was analysed by TGA/DTG technique and revealed that the crystal was stable up to 162 °C. Density functional theory calculations such as the value of the HOMO and LUMO energy gap, the parameters of the molecular electrostatic potential, the global reactivity and thermodynamic properties of the compound TMPPc were also performed using the DFT/B3LYP method with the level of the 6-311G (d, p) basis set.

The phytochemical, antioxidant, and anti-inflammatory potential of root (ethanol and aqueous) extracts of Combretum glutinosum was investigated in this study. Their antioxidant activity was determined using an in vitro DPPH radical scavenging activity assay. The ethanol extract had the lowest IC₅₀ (0.055 mg/mL), which is comparable to vitamin C. Phytochemical screening of extracts revealed the presence of sterols and polyterpenes, polyphenols, alkaloids, flavonoids, catechin tannins, gallic tannins, saponosides, terpenoids, mucilages, anthocyanins, volatile oils, and cardiac glycosides. The extracts significantly inhibit the development of paw edema induced by carrageenan. Anti-inflammatory studies showed that the inflammation inhibition potential of 200 mg/kg body weight of all extracts was significantly lower than the standard diclofenac (20 mg/kg) in the first hours. At the third hour, the inflammation inhibition potential of ethanolic and aqueous extracts was significantly higher than that of the standard. This study revealed that Combretum glutinosum extracts have anti-inflammatory effects and can act as an effective antioxidant.

Chiral metallic drugs are becoming the hottest point of discussion in the field of medicinal chemistry. As we know that more than 80% drugs are chiral in nature, and prescribed in the racemic form. The main problem with chiral drugs is the different biological activities of different enantiomers. This is because the human body has a chiral environment, as there is the presence of protein, carbohydrates, enzymes, and other chiral macromolecules. Hence, if a chiral anticancer drug is being prescribed to the patient in the racemic form, it means two or more drugs are being prescribed. Therefore, the chiral separation and analysis of chiral anticancer drugs are important for improving the quality of chiral drug medication. Many metal complexes are used as anticancer drugs, but the conditions become more critical if they have chirality or a chiral moiety, because of which they exist in two or more forms. Because of the presence of chirality or chiral moiety, the complex of metals is termed a chiral metallic complex. Of course, the enantioseparation of the chiral metallic complexes must be done before their prescription. Enantioseparation of the chiral metallic complex will not only provide a pharmaceutically active form to the patient but also reduce the side effects caused by the racemic mixture. Hence, the accessible article reviews the chiral metallic complexes having ruthenium, osmium, palladium, gold, silver, and platinum, etc. as central metal atoms. Besides, the future perspectives regarding the chiral metallic anticancer drugs and the role of their enantioseparation are also discussed.