Monoclinic Research Articles

Investigating the Influence of Sintering Temperature and Ascertaining Hopping Path in Sodium Superionic Conducting Electrolytes for Sodium-Ion Batteries

Recently, sodium super-ionic conducting (NASICON) type solid electrolytes have gained significant interest as potential candidates for next-generation batteries due to their exceptional properties such as high ionic conductivity, affordability, and remarkable chemical and electrochemical stability. Therefore, NASICON type solid electrolyte (Na3Zr2Si2PO12) is synthesized by solution assisted-solid state reaction (SA-SSR) method and sintered at three different temperatures, 1200 ℃, 1250 ℃ and 1300 ℃. Various experimental techniques are used to characterize and optimize the sintered electrolytes. The Rietveld refinement of X-ray diffraction pattern of prepared electrolytes revealed the monoclinic crystal structure having 3-dimension hopping channel for sodium ion migration through triangular bottleneck area. Complex impedance spectroscopy revealed, the highest bulk and grain boundary conductivity are found, 4.05 mS cm-1 and 0.31 mS cm-1, respectively, for the sample sintered at 1250 ℃. Using optimized electrolyte, sodium half-cell is demonstrated with Na3V2P3O12 (NVP) as cathode. The assembled cell delivers maximum discharge capacity 101.6 and 84.45 mAh g-1 at the current density 10 and 40 mA g-1, respectively with good capacity retention (~95.02%) upto 50 cycles. Figure 1

Synthesis, structure and Hirshfeld surface analysis of pyridinium derivative crystals

Slow evaporation methods were employed to grow single crystals of 3-acetylpyridinium picrate (I), 4-acetylpyridinium picrate (II), and pyridin-4-ylmethanaminium 2,2-diphenylacetate hydrate (III). Crystal (I) and (III) crystallize triclinic crystal system with a centric (Pī) space group and (II) crystallize in a monoclinic system with a centric (P21/c) space group. Various types of non-covalent interactions take part successfully in the construction of 3D networks in the compounds. Optical reflectance measurements showed 2.57, 2.66, and 4.45 eV as band gaps for (I), (II) and (III) respectively. TG/DTA analysis reveals the thermal pattern of the compounds. Intermolecular interactions are quantified by Hirshfeld surface analysis.

Pinaverium bromide.

The structure of pinaverium bromide (systematic name: 4-[(2-bromo-4,5-di-meth-oxy-phen-yl)meth-yl]-4-{2-[2-(6,6-dimethyl-2-bi-cyclo-[3.1.1]hepta-nyl)eth-oxy]eth-yl}morpholin-4-ium bromide; C26H41Br2NO4), was determined at 110 K. It has monoclinic (P21) symmetry. It is of inter-est with respect to its anti-inflammatory properties. The asymmetric unit contains two independent mol-ecules, one of which exhibits disorder of the bi-cyclo terminal group (occupancy factors: 0.78 and 0.22).

Structural, optical and magnetic properties of chemically grown copper oxide nanoparticles: An insight into anticancer activities

Self-assembling nanorods like copper oxide (CuO) nanoparticles (NPs) have been successfully synthesized using two different copper cationic precursors to investigate their structural, optical, and magnetic properties. These NPs are employed in anticancer applications. Both the CuO-NPs have been tested for their toxicity on human cells. The XRD patterns confirm the formation of monoclinic crystal structures for both the systems. The FESEM microstructural surface morphology shows high agglomeration and a typical elemental composition is evaluated from EDAX analysis. The HRTEM analysis reveals high crystalline CuO nanorods with diameters in the range of 60 ∼ 94 nm and 09∼ 22 nm for two different nanoparticles named CuO-NPs1 and CuO-NPs2, respectively. The optical band gap of CuO-NPs has been calculated from UV–visible absorption spectra and is found to be 2.18 eV and 2.55 eV for CuO-NPs1 and CuO-NPs2, respectively. FTIR analysis provides insights into the chemical compositions of both the CuO-NPs. Magnetization study using vibrating sample magnetometer (VSM) indicates antiferromagnetic-like properties associated with weak ferromagnetic behaviour. Cytotoxicity tests on MCF-7 cell lines show that CuO-NPs2 exhibit more pronounced effect with IC50 of 22.95 μg/mL. The toxicity of both the CuO-NPs are also assessed using human lymphocytes, suggesting that CuO-NPs could be promoted as anticancer agents while remaining non-toxic to biological systems.

Mer-[Ni(dien)2]Cl2.H2O and mer-[Ni(dien)2](NO3)2 complexes (dien= diethylenetriamine): Synthesis, physical, computational studies, antioxidant activity, and their use as precursors for Ni/NiO nanoparticles’ preparation

Two new Ni(II) complexes, mer-[Ni(dien)2]Cl2.H2O (I) and mer-[Ni(dien)2](NO3)2 (II), where dien= diethylenetriamine and mer refers to meridional coordination, have been prepared under ambient conditions. Complex (I) crystallizes in the P21/c space group of the monoclinic system, with a = 13.5000(4) Å, b = 8.7170(3) Å, c = 13.9430(4) Å, β = 102.091(2)° and V = 1604.41 Å3, whereas complex (II) crystallizes in the Pbca space group of the orthorhombic system, with a = 8.8117(6) Å, b = 14.0023(8) Å, c = 26.7603(17)Å and V = 3301.79 Å3. Both structures contain the [Ni(C4H13N3)2]2+ cation, together with two chloride anions and a water molecule for (I) and two nitrate anions for (II). The metal centre is coordinated to six nitrogens of the neutral dien ligands in a slightly distorted octahedral geometry. The two compounds have been characterised by FTIR and UV-Vis spectroscopy. Their morphology and size were studied by scanning electron microscopy (SEM). The thermal behaviour of the title compounds was also investigated. Calcination of the two complexes in air yielded Ni/NiO nanoparticles. The structures of both complexes were optimised and their simulated geometric parameters and vibrational modes were discussed and correlated with the experimental data. The antioxidant potential of both complexes was evaluated using DPPH, ferric reducing power tests and phosphomolybdenum assay.

New polymorph of N-benzoyl-morpholine-4-carbothioamide with ten crystallographically independent molecules in the asymmetric unit: Crystal structure, Hirshfeld surface analysis and Density functional theory calculations

Herein, facile synthesis, single crystal X-ray diffraction (SC-XRD) structure, Hirshfeld surface (HS) analysis and Density functional theory (DFT) calculations of N-benzoyl-morpholine-4-carbothioamide 5(a) are presented. Hence, the synthesized compound, C12H14N2O2S 5(a), crystallizes in monoclinic crystal system having space group of P 21 with a = 22.2226 (9) Å, b = 11.7520 (3) Å, c = 24.9361 (8) Å, α = 90°, β = 111.054 (4)°, γ = 90°, Z = 20 and V = 6077.6 (4) Å3. The asymmetric unit of 5(a) contains ten crystallographically independent molecules, where the morpholine and benzene rings are in respective chair and planar conformations. In the crystal structure, some of the intermolecular, N—H···O, C—H···O and C—H···S, hydrogen bonds link the molecules into a 2D-network parallel to (010), enclosing R22(10) and R22(24) ring motifs, when viewed down the b-axis direction. Furthermore, contribution of the remaining hydrogen bonds consolidates a 3D-architecture. Similarly, HS analysis clarified the importance of hydrogen atom contacts with the major contributions of H…H (46.7 %), H…S/S…H (21.1 %), H…C/C…H (16.5 %), and H…O/O…H (12.5 %). Thus, hydrogen bond and van der Waals interactions play major role in the crystal packing. Finally, optimum molecular structure of compound 5(a) was related to the experimentally determined one employing DFT at B3LYP/6–311++G(d,p) level. Subsequently, the geometry of the optimized and most stable conformation turned out to be complementary with the crystal structure. The computational calculation of compound 5(a) revealed the molecule to be chemically hard in nature with high energy intrinsic reaction pathway. The associated band gap predicted compound 5(a) to be a wide band gap material. The intrinsic reaction pathway predicts hard-core behavior of the molecule.

Bis[μ-3-(pyridin-2-yl)pyrazolato]bis-[acetato-(3,5-dimethyl-1H-pyrazole)-nickel(II)

The title compound, [Ni2(C8H6N3)2(C2H3O2)2(C5H8N2)2] or [Ni(μ-OOCCH3)(2-PyPz)(Me2PzH)]2 (1) [2-PyPz = 3-(pyridin-2-yl) pyrazole; Me2PzH = 3,5-dimethyl pyrazole] was synthesized from Ni(OOCCH3)2·4H2O, 2-PyPzH, Me2PzH and tri-ethyl-amine as a base. Compound 1 {[Ni2(C30H34N10Ni2O4)]} at 100 K has monoclinic (P21/n) symmetry and the mol-ecules have crystallographic inversion symmetry. Mol-ecules of 1 comprise an almost planar dinuclear NiII core with an N4O2 coordination environment. The equatorial plane consists of N3,O coordination derived from one of the bidentate acetate O atoms and three of the N atoms of the chelating 2-PyPz ligand while the axial positions are occupied by neutral Me2PzH and the second O atom of the acetate unit. The Ni atoms are bridged by the nitro-gen atom of a deprotonated 2-PyPz ligand. Compound 1 exhibits various inter- and intra-molecular C-H⋯O and N-H⋯O hydrogen bonds.

Nucleation, crystal growth, XRD, optical, electrical, PC, SEM, SHG and Z-scan analysis of LHPP for NLO and optical limiting application

High-quality organic L-histidinium 4-nitrophenolate 4-nitrophenol (LHPP) single crystals were grown using an aqueous solution. The crystals were grown using slow evaporation solution technique (SEST) at a temperature of 40°C using a constant temperature bath (CTB). Nucleation growth rates were monitored for various durations using an optical microscope. The crystalline perfection was confirmed through sharp, high-intensity diffraction peaks observed in the theoretical and experimental powder X-ray diffraction (PXRD) analysis, which also confirmed the monoclinic crystal structure with the noncentrosymmetric P21 space group. The crystallite size and strain were calculated using Williamson–Hall coefficient. Vibrational frequency assignments of LHPP were determined using FTIR spectroscopic analysis. Optical properties were studied using UV–Vis NIR spectroscopic studies, which showed that the crystals have very low absorption and high transmittance in the entire visible region. Additionally, the optical energy bandgap (Eg) was calculated and found to be 6.15[Formula: see text]eV. Luminescence properties were studied using fluorescence (FL) analysis. Dielectric investigations were subjected to varying frequencies to study the suitability of the crystal for transistor application. The positive photoconductive (PC) nature of the crystal was confirmed using photoconductivity studies to confirm suitability for photodetector devices that measure the intensity of light rays. Etching studies revealed the growth pattern and the formation of different kinds of etch pits. The surface morphology was studied using scanning electron microscopy (SEM) and electrochemical studies were also carried out. The relative second harmonic generation (SHG) efficiency of the material was also examined and found to be 1.34 times that of standard KDP. The optical limiting and higher-order nonlinear optical (NLO) properties of the grown crystals were studied by the [Formula: see text]-scan method using a Nd: YAG laser functioning at 532[Formula: see text]nm.

Structural, spectroscopy, nonlinear optical, and laser damage threshold analyses of sodium guanidinium bis(4-methylbenzenesulfonate) hydrate (NGMBS) crystal

Sodium guanidinium bis(4-methylbenzenesulfonate) hydrate (NGMBS) crystallized in the monoclinic crystal system with non-centrosymmetric space group P21. The mixed ionic crystal assembly was stabilized by N H⋯O hydrogen bonding involving guanidinium ion and with Na+ ions surrounded by aqua ligands and S–O oxygen atoms completing six coordination involving with coordinate covalent and ion–dipole interactions. A supramolecular assembly in two dimensions (along the a and b-axis) is possible by H-bonding which brought the Na+ within a distance of 3.6493 Å. The two 4-methylbenzenesulfonate ligands in one formula unit were not identical and exhibited structural variations. Hirshfeld analyses indicated significant interaction due to N⋯H, O⋯H, and Na+ … O. The vibrational bands were ascertained using FTIR. A cut-off wavelength of 273 nm and bandgap of 4.50 eV were estimated from UV–visible spectroscopy. The compound excited at 260 showed emission at 291 nm. Colour purity up to 95.62 % was estimated from chromaticity calculations. Kurtz-Perry's method confirmed that NGMBS showed NLO properties 1.5 times than KDP. The NGMBS crystal demonstrated superior resistance to LASER induced damage as compared to urea.

Self-assembled tin(IV) organic-inorganic hybrids: Synthesis, spectral, structural, and Hirshfeld surface analysis of bis(thiomorpholinium) hexahalostannate(IV)

At room temperature, organic-inorganic hybrids, including bis(thiomorpholinium) hexachlorostannate(IV) hydrate (1) and bis(thiomorpholinium) hexabromostannate(IV) (2), were synthesized from thiomorpholinium chloride/bromide. The hybrids underwent characterization using, IR, elemental, NMR, TGA, DRS and PL spectroscopy, along with single-crystal X-ray diffraction (SCXRD). SCXRD confirms compounds are crystallized in a monoclinic system exhibiting centrosymmetric space groups (C2/candP21/c for (1) and (2)). The SCXRD structures of the hybrids unveiled significant H-bonded interactions between the thiomorpholinium cation and the SnCl62-/SnBr62- anions. At room temperature, optical absorption measurements revealed band gaps of 3.91 eV for (1) and 3.00 eV for (2).TGA confirmed the proposed formulas of the compounds.BVS calculations conducted on SnCl62- and SnBr62- anions yielded values of 4.01 and 3.94, respectively. Fingerprint plots were employed to identify and quantify the proportion of hydrogen bonding interactions.

Phase identification and photophysical characteristics of vanadate-based nanophosphors for lighting and latent fingerprinting applications

Monoclinic structure-based Er3+-activated Ba2BiV3O11 nanophosphors have been developed via an easy and cost-efficacious urea-aided solution combustion (SC) procedure. Various spectroscopic and structural investigations thoroughly examine the produced powders. The crystal structure has been resolved by employing a combination of X-ray diffraction (XRD) and the Rietveld refinement practice. The developed powdered nanosamples are crystallized in a monoclinic crystal system with P21/a space group. Further, to evaluate the composition of elements and their relative distribution, energy dispersive X-ray (EDAX) analysis was performed. The band gap values for the host matrix and the optimal nanophosphors were measured using a DR spectrophotometer; the obtained values were 3.47 eV and 3.40 eV, respectively. The strongest excitation peak at 381 nm is closely-matched with the characteristic wavelength of commercialized near ultraviolet (NUV) based LEDs. The characteristic emission spectra of Ba2Bi1-xErxV3O11 (x = 0.01–0.1) phosphors show the strongest emission at 553 nm (4S3/2 → 4I15/2). Additionally, photometric parameters such as quantum efficiency (86 %), color coordinates (x = 0.2568 and y = 0.4551), and correlated color temperature (CCT = 7722 K) are obtained from PL data and are strongly advised for use in wLEDs, color displays, imaging, lighting, and latent fingerprint applications.

[formula omitted] leaves mediated combustion synthesis of Tb[formula omitted] doped Zn2V2O7 nanoparticles: Color tunable photoluminescence and electrochemical studies for display and supercapacitor applications

A new series of Tb3+ doped Zn2V2O7 (ZV) nanoparticles (NPs) at different concentration from 1 to 9 mol% was synthesized by Menthaspicata leaves extract mediated solution combustion method. On Tb3+ doping, the diffraction pattern matches well with the monoclinic crystal structure with the C2/c(2/m) space group of ZV host matrix. The surface morphology tuned from irregular shaped NPs to hexagonal shaped NPs with variation in dopant concentration. The crystallite size estimated from Scherrer’s method matches well with the transmission electron microscopy analysis. The optical band gap determined from Tauc’s plot utilizing UV–Visible absorption was tuned from 3.061 to 3.035 eV with increase in dopant concentration. Under 266 nm excitation, the emission of Tb3+ ions from Tb3+-doped ZV NPs is observed, with the intensity of emission showing sensitivity to the concentration of Tb3+ ions. The optimal doping content is determined to be 7 mol %. The CIE coordinates clearly indicates the tuning of the emission color from green to blue region with increase in dopant concentration. The average color coordinated temperature was found to be 7895 K showing the cooler appearance. Further, cyclic voltammetry analysis offers valuable insights into redox reactions, electrode kinetics, and overall electrochemical behavior, while Electrochemical Impedance Spectroscopy (EIS) provides information on ion transport kinetics. Galvanostatic Charge–Discharge (GCD) analysis revealed supercapacitance values ranging from 79.43 to 133.26 F/g at 10 mV/s with increasing dopant concentration. These findings underscore the potential of this material for use in energy storage and display technology applications.

A new 3D Zn(II)‐based MOF with gra topological network as a photocatalyst for antibiotic degradation

A novel zinc‐based metal–organic framework (Zn‐MOF), designated as [Zn3(L)(bpyp)2(HCOO)3·2DMF·H2O] (1), was synthesized using 2,5‐bis(pyrid‐4‐yl)pyridine (bpyp), 1,3,5‐benzenetricarboxylic acid (H3L), and Zn(CH3COO)2·2H2O in a DMF solution. Single‐crystal X‐ray diffraction analysis revealed that MOF 1 crystallizes in the monoclinic system with a C2/c space group, featuring a (3,5)‐connected binodal network. The structural integrity and characteristics of MOF 1 were confirmed by Fourier transform infrared (FT‐IR), thermal gravimetric analysis (TGA), powder X‐ray diffraction (PXRD), and Brunauer–Emmett–Teller (BET) analyses, showing type IV isotherms indicative of microporous structures. The photocatalytic efficiency of MOF 1 was evaluated for the degradation of various antibiotics under UV light, with nitrofurantoin (NFT) demonstrating the highest degradation rate of 83.9% at an optimal concentration of 40 ppm and catalyst loading of 5 mg. The degradation process followed a pseudo‐first‐order kinetic model with a rate constant of 0.02492 min−1. Radical trapping experiments identified superoxide radicals (O2˙−) and holes (h+) as the predominant reactive species, while hydroxyl radicals (˙OH) played a negligible role. Reusability tests over four cycles confirmed the stability and durability of MOF 1, with consistent photocatalytic performance and unchanged structural morphology as evidenced by PXRD and SEM analyses. The proposed mechanism involves photoinduced electron–hole pair generation, with subsequent formation of reactive oxygen species (ROS) facilitating NFT degradation. This study highlights MOF 1 as a promising photocatalyst for environmental remediation, specifically for the efficient degradation of pharmaceutical contaminants in aquatic systems, providing insights into its structural properties, photocatalytic activity, and underlying degradation mechanisms.

One-step synthesis of 2-Methyl-2,4-Diphenyl-2,3-Dihydro-1H-Benzo[b][1,4]diazepine: Investigating crystal structure, hirshfeld surface analysis and supercapacitor applications

This study reports the synthesis, spectroscopic characterization and detailed crystal structure analysis of a benzodiazepine compound, 2-methyl-2,4-diphenyl-2,3-dihydro-1H-benzo[b][1,4]diazepine, synthesized from 1,2-phenylenediamine and acetophenone. The crystal structure, determined via single crystal X-ray analysis, reveals the compound's placement within the monoclinic system with the P 21/c space group. The asymmetric unit comprises the main molecule and an uncoordinated water molecule linked through an intramolecular O–H···N hydrogen bond. The crystal packing is influenced by centrosymmetric dimers formed by uncoordinated water molecules through O–H···N hydrogen bonds, along with weak C–H···π interactions. Hirshfeld surface analysis highlights the significance of H … H and H … C/C … H interactions in the crystal packing, providing insight into the intermolecular forces at play. Supercapacitance performance of the GCPE/LDABA electrode was assessed and specific capacitance value of 17.89 mF g−1 was achieved in a 0.1 M Na2SO4 electrolyte. Long-term stability of the GCPE/LDABA electrode was maintained up to 2000 cycles. This study not only elucidates the structural features of the title compound but also sheds light on its potential utility through an investigation into its electrochemical performance via supercapacitor application.

Insights into Co (II)-based hybrid materials for photocatalytic and antioxidant applications

Metal-organic materials are widely used as scaffolds to create porous materials for various applications. However, research on solid compositions from hybrid materials (HB) is limited. This study examines two hybrid components using spectroscopic techniques and single crystal X-ray diffraction. The crystal structure analysis reveals a monoclinic system for compounds Co(HCO2)2·2H2O (I) and (C6H10N2)2[CoCl4]Cl2 (II) in the P21/c space group. Compound I features cobalt octahedra with coordinated formate ions and water molecules, while compound II contains organic cations, anions, and free chlorides with interconnected structural motifs. UV light at 400 nm induces high photocatalytic activity in both complexes, leading to significant degradation rates within 80 minutes. Trapping experiments identify activated species as h+ and •O2−. Antioxidant activity assessments highlight their antioxidative potentials.

Microcube formation and characterization of cobalt and nickel selenite dihydrate: Thermal, spectral, and dielectric insights

This paper outlines the template-free preparation of cobalt and nickel selenite dihydrate microcubes using a simple precipitation method from aqueous solutions at room temperature. Structural analysis revealed the formation of pure, well-crystallized isostructural cobalt and nickel selenite dihydrate, exhibiting monoclinic crystal systems of space group P21/n. Thermal analysis showed distinct decomposition patterns for both compounds, highlighting their thermal stabilities. The intermediate formed after water loss were stable up to ∼550 °C, and crystallized before decomposing into their respective oxides via SeO2 sublimation. Scanning electron microscopy (SEM) images illustrated the presence of irregular-sized well-defined microcubes with smooth surfaces and sharp edges, distributed across the material. The formation of these microstructures is likely driven by self-aggregation and the Ostwald ripening process. Dielectric studies on pelletized materials revealed higher dielectric constants at low frequencies with minimal dielectric loss. CoSeO3⋅2H2O exhibited higher dielectric constants than NiSeO3⋅2H2O due to the larger ionic radius of Co2+ ions, which leads to a greater degree of polarization compared to Ni2+ ions. The considerably higher dielectric constant with an insignificant amount of dielectric loss indicates the materials’ potential for applications in dielectric and microwave technologies.

Exploring the anticancer activity of 1-(2-methyl-3-furoyl)-4-phenyl-3-thiosemicarbazide and its Mn(II) complex: Synthesis, spectral, crystal structures, and Hirshfeld surface analysis

The chemistry of mixed ligand transition metal complexes has been of interest of researchers owing to its diverse application and bonding features. Herein, a new thiosemicarbazide derivative namely 1-(2-methyl-3-furoyl)-4-phenyl-3-thiosemicarbazide (HmfpTSC) has been synthesized along with its [Mn(mfpTSC)2(o-phen)] (C1) complex. The prepared ligand (HmfpTSC) and the complex have been confirmed via spectroscopic and single-crystal X-ray data. The HmfpTSC and complex crystallize in a monoclinic crystal system with space group P21/c and P21/n, respectively. HmfpTSC behaves as a uninegative bidentate ligand and its two-unit binds with metal ion along with one unit of o-phen. Using Hirshfeld surface analysis, the weak interactions seen in HmfpTSC and complex have been quantitatively investigated. The MTT assay was used to assess the cytotoxicity of HmfpTSC and [Mn(mfpTSC)2(o-phen)] complex against Dalton's lymphoma cells. Further, the mechanism of anticancer action of ligand and complex was investigated through DAPI, AO/EB staining, and flow cytometry. The both AO/EB and DAPI staining provided compelling evidence of complex-induced cellular and nuclear changes consistent with apoptosis and necrosis.

Na2.64Mn1.64(MoO4)3 and Na2.62Ni1.69(MoO4)3: Physicochemical investigations and electrochemical properties as 3.5 V class positive electrode material for Na-batteries

Powders of two new mixed molybdates Na2.64Mn1.64(MoO4)3 (1) and Na2.62Ni1.69(MoO4)3 (2) have been prepared via a solid-solid reaction. They are isostructural, both crystallizing in monoclinic system (S. G.: C2/c), Z = 1, and the unit cell parameters a = 12.74109 (18) Å, b = 13.69390 (15) Å, c = 7.20028 (8) Å, β = 112.4314 (7) °, V = 1161.22 (2) Å3 (1), and a = 12.6368 (2) Å, b = 13.3633 (2) Å, c = 7.08501 (10) Å, β = 111.9248 (10) °, V = 1109.91 (3) Å3 (2). The structure consists of a 3D network of corners and edges sharing [MoO4] and [MO6] polyhedral, delimiting tunnels in which the Na ions partly site. The samples were investigated by powder X-ray diffraction, infrared spectroscopy, and scanning electron microscopy coupled to energy-dispersive X-ray spectroscopy (SEM-EDX). The vibrational study confirms the existence of the MoO42− functional groups. Laser Raman spectroscopy showed that the MoO42− tetrahedra in the two compounds are more regular, suggesting high symmetry for the compound. The as-synthesized compounds are fiber-like grains with an average length of 10−1 μm. FT-IR spectra showed the presence of all the functional groups present in the compounds. Magnetisation measurements showed their paramagnetic behaviour. The title compounds were characterized by cyclic voltammetry (CV), electrochemical performance and limiting factors are also applied as electrode material for Na-ion batteries at room temperature. Benefiting from these advantages, between 1.5 V and 4.6 V, (1) and (2) deliver high specific capacities of 230 and 160 mA h g−1 after 60 cycles, and good rate performances, respectively. It can also be inferred that the prepared electrocatalyst showed for both phases excellent Hydrogen Evolution Reaction (HER) performance with an overpotential of 531 mV for Mn and 512 mV for Ni, required to afford a current density of 10 mA cm−2.

Molecular structures, DFT calculations, in silico molecular docking, predicted pharmacokinetics and biological activities of N-(quinolin-8-yl)-2- pyridine/pyrazine carboxamide compounds

New N-(quinolin-8-yl)pyrazine/pyridine-2-carboxamide derivatives were prepared through condensation reaction of 8-amino-quinoline with the appropriate carboxylic acids to afford 5-methyl-N-(quinolin-8-yl)pyrazine-2-carboxamide (HL1) and 5‑chloro-N-(quinolin-8-yl)pyridine-2-carboxamide (HL2). Single crystal X-ray crystallography analysis unambiguously reveals that the asymmetric units of C15H12N4O (HL1) and C15H10ClN3O (HL2) belong to the monoclinic system with P121/1space group. Density functional theory (DFT) reveals that the chemically active sites of HL1-HL3 are situated on the O-atoms and N-atoms. Molecular docking of the compounds with calf thymus DNA (CT-DNA) and bovine serum albumin (BSA) receptors demonstrated favourable binding scores within the active binding sites. In silico pharmacokinetic results suggest that the compounds obey Lipinski rule, which is a key requirement for a potential drug candidate

Polymorphism in 5-methylsalicylic acid: Insights into relative thermal behavior, luminescent properties, crystal structure, and Hirshfeld surface analysis

Polymorphs play an important role in mediating the physical and chemical properties of compounds. Three polymorphs were obtained from different solvents used in crystallization. A new polymorph of 5-methylsalicylic acid (γ-MSA) were obtained from acetic acid. The polymorphs α-MSA and β-MSA crystallized from water, and the mixed solvent containing methanol and water, respectively. The novel morphology of γ-MSA has been characterized by single–crystal X–ray diffraction, IR spectroscopy data, and powder X-ray diffraction. Single-crystal X-ray diffraction analysis shows that γ-MSA belongs to the monoclinic system with the P21/c space group. The parameters are listed as the following: a = 7.2795(5) Å, b = 15.2560(7) Å, c = 6.7170(4) Å, β=100.834(7)°, V = 762.83(8) Å3. In the novel polymorphic structure, classical hydrogen bonds of O–H···O can be obviously observed, through which a supramolecular architecture will be generated. Apart from the classical hydrogen bonds, the weak hydrogen bonds of C–H⋯O can be only found in form γ-MSA. The luminescent maximal are 394, 398 and 406 nm for α-MSA,β-MSA and γ-MSA, respectively. The order of the luminescent maximal peaks is listed as the following: α<β<γ. Single-crystal X-ray diffraction analysis results reveal that the order of the stacking interactions and the dihedral angles occurred between the carboxylic group and phenyl ring presents the following: α<β<γ. The Hirshfeld analysis further confirms that there exists the same sequence of the C···H intercontacts in α-, β- and γ-polymorphs. The contribution of the H···O/O···H close contacts in γ-MSA is the largest among these polymorphs, being confirmed by differential scanning calorimeter (DSC) data, which is in a good agreement with that of melting point. On the basis of analysis of DSC data and the fusion rules, the enthalpies (ΔH) and entropies (ΔS) can be estimated to be 29.5 kJ mol-1 and 69.4 J K-1 mol-1 for α; 31.1 kJ mol-1 and 72.8 J K-1 mol-1 for β, and 35.4 kJ mol-1 and 74.5 J K-1 mol-1 for γ), and these polymorphs are monotropically related. The sequences of melting point, enthalpies and entropies can be proposed: α<β<γ.