This article presents an in-depth study on the antioxidant activity and structural properties of 3 ',4-dimethyl-3phenyl-3 ',4 '-dihydro-1 ' H,4H-spiro[isoxazole-5,2 '-naphthalene]-1 '-one, referred to as DPS. Crystallographic analysis revealed its orthorhombic crystal system with a space group of P212121, elucidating its unique structure. Hirshfeld surface analysis highlighted the intermolecular interactions governing the crystal packing. The antioxidant activity of DPS was evaluated using DPPH and ABTS radical scavenging assays, showing significant activity with IC50 values of 0.078 mg/mL and 0.059 mg/mL, respectively. The integrated DFT-molecular docking approach provided valuable insights into the electronic properties of the DPS ligand and its binding affinity toward NADPH oxidase. These results highlight the antioxidant potential of DPS and warrant further investigation.

The synthesis of the [NiII(H2L3)]SCN 1 and [CuIIL4(SCN)]& sdot;2DMF 2 complexes was carried out using the proligand 1-thiocarbamoyl-3,5-dimethyl-5(thiosemicarbazido)-2-pyrazoline (H2L2); derivative from 2,4-pentanedione bis (thiosemicarbazone) (H3L1), the thiocyanate ion and the divalent metal ions of nickel and copper. Complex 1 was prepared by reaction of the cyclic ligand H2L2 with a solution containing the SCN-, Ni2+ and Cu2+ ions. Single crystal X-ray diffraction (SC-XRD) study revealed that this complex is a cationic mononuclear complex of NiII with a new generated ligand (H2L3)-, arising from the establishment of a bond between the nitrogen atom of the thiocyanate and the central carbon atom of the organic ligand (H3L1). The geometry around the nickel is square planar of MN2S2 mode, while the second thiocyanate played the role of counter-anion in the Ni(II) complex structure. With a solution containing only the thiocyanate and the cupric ions, the proligand H2L2 leads in two steps to the complex 2 which is based on an original heterocyclic ligand issue also from the reaction of thiocyanate ion with H3L1 ligand, but in different way. The crystallographic study revealed a new coordination sphere of square planar geometry where the new ligand (L4) is in tridentate mode (N2S) and a thiocyanate ion is linked in terminal mode by the nitrogen atom. In addition to XRD, the title complexes have been characterized using FTIR, UV-Vis, as well as Hirshfeld surface analysis and plausible mechanisms have been proposed to explain the in situ formation of the new ligands. Furthermore, the synthesized coordination complexes were studied by PASS, molecular docking, and in silico ADME assessments to evaluate the biological activity, molecular interactions, and pharmacokinetic properties. PASS Prediction identified enhanced antineoplastic activity in ligand-metal complexes, confirmed by molecular docking against Cyclin-dependent kinase 2 (CDK2) receptor for a xenograft cancer.

[Mg(H2O)4][(VO)2(PO4)2] 2 O) 4 ][(VO) 2 (PO 4 ) 2 ] has been successfully synthesized in the M 2+-V4+ 4+-P-O system through hydrothermal synthesis route. It was characterized using single-crystal X-ray diffraction, Fourier Transform Infrared Spectroscopy (FT-IR), scanning electron microscopy (SEM), and thermal stability analysis (TG-DTA). [Mg(H2O)4] 2 O) 4 ] [(VO)2(PO4)2] 2 (PO 4 ) 2 ] crystallizes in the tetragonal system (S.G.: I 4/ m ), with the cell parameters: a = 6.2497(3), b = 6.2497(3), c = 13.4194(8) & Aring;, V = 524.145 & Aring;3 , 3 , and Z = 2. The structure consists of vanadyl phosphate layers [VO (PO4)]2 infinity , 4 )] 2 infinity , constructed from O-vertices sharing [VO5]-square 5 ]-square pyramids and [PO4] 4 ] tetrahedral, which are separated by layers of [MgO6] 6 ] octahedral linked to [VO5] 5 ] by Mg-O-V O - V bonds along c-axis. FT-IR and Raman studies confirmed the characteristic bands of phosphate and the vanadium (IV) groups. Thermogravimetric analysis of the compound was also used to study its thermal behavior. Furthermore, the catalytic efficiency of the title compound in the reduction by NaBH4 4 of three nitrophenol isomers (ortho-, meta-, and para-) to their corresponding aminophenols was tested. All three nitrophenol isomers could be reduced in 30 s in the presence of the title compound. First-principles calculations employing density functional theory (DFT) explored the structural, electronic, and optical properties. These computations were utilized to analyze the band structure, density of states, reflectivity, absorption coefficient, refractive index, and extinction coefficient. Examining the band structure and density of states (DOS) reveals that the material possesses a band gap of 2.79 eV.

In the present work, single, double and triaxial (tensile/compression) strains were applied to lithium borohydride LiBH4 using Density Functional Theory (DFT) based on Perdew-Burke-Ernzerhor for solids (PBEsol) approach. The results show that the structural properties change with the deformation amplitude. The total density of state (TDOS) and partial density of state (PDOS) studies show that the LiBH4 complex hydride is an insulator with an energy band gap of 6.73 eV and the width of the valence and conduction bands vary with the change of the strain amplitude. The deformation energy shows that triaxial deformation on LiBH4 complex hydride requires more energy than single and double strains. Hence, these deformations are found responsible for the decrease of the thermodynamic properties of LiBH4 hydride. Specifically, under a maximum uni/bi/triaxial compressive strain of epsilon = -9%, the enthalpy of formation and decomposition temperature decrease by 3.25 %, 7.59 %, and 36.54 %, respectively. While, under a maximum uni/bi/triaxial tensile strain of epsilon = +9 %, the enthalpy of formation and decomposition temperature decrease by 3.85 %, 11.83 %, and 26.44 %, respectively, compared to unstrained hydride. Consequently, the findings are in excellent agreement with the standards of the U.S. Department of Energy (DOE) (Delta Hf = -40 Kj/mol.H2 and Td = 289-393 K) for hydrogen storage in the solid state.

In the current study, we report the synthesis, structural determination, and both in vitro and in silico antioxidant assessment of 2-(1-(3-methyl-1-oxo-1,2,3,4-tetrahydronaphthalen-2-yl)ethyl)malononitrile. The title compound was synthesized via the 1,4-Michael addition reaction of malononitrile with (E)-2-ethylidene-3-methyl-3,4-dihydronaphthalen-1(2H)-one in the presence of piperidine. The molecular structure of the synthesized compound was elucidated using various techniques such as 1H-NMR, 13C-NMR, IR, elementary analysis (AE) and confirmed by mass spectrometry (MS), as well as by the X-ray diffraction (XRD) analysis. Notably, the XRD study showed the investigated compound crystallizes in the triclinic system (S.G.: P-1). The target compound was evaluated for its antioxidant ability employing the Free radical scavenging (DPPH), Ferric reducing power (FRAP), and Phosphomolybdenum (PM) tests. The findings revealed that the compound displays an interesting antioxidant power. Furthermore, the molecular docking results show that the studied compound has a potential antioxidant effect, producing stable intermolecular interactions towards antioxidant proteins encoded in the protein data bank (PDB) by 1N8Q, 1OG5, 2CDU, and 4JK4, respectively.

In this paper, using density functional theory (DFT), we investigate the impact of mechanical treatment in terms of uniaxial and biaxial strains on both hydrogenation states of magnesium compounds i.e. H2-free magnesium (Mg) and preliminarily hydrogenated magnesium (MgH2). The thermodynamic properties calculation shows that applying uniaxial and biaxial strains on the H2-free magnesium does not significantly affect the formation enthalpy and decomposition temperature of the hydride phase. On the other hand, strain energy contributions on preliminarily hydrogenated magnesium are found able to decrease and improve the formation enthalpy and the decomposition temperature, making it feasible for the operational conditions of proton exchange membrane (PEM) fuel cells at 289 -393 K. Also, the findings demonstrate that the kinetic properties in terms of hydrogen atom diffusion show a decrease in the activation energy barrier, which means an improvement in the kinetics properties faster than that of strain-free magnesium hydride. These results potentially provide better clues for the development of a magnesium-based metal hydride for hydrogen storage applications. (c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

In this study, we perform a computational experiment to inspect the impact of native Zr/Ni defects and H-doping atoms on the electrochemical and thermodynamic properties of the AB-type ZrNi alloys. The Korringa-Kohn-Rostoker (KKR) method integrated with the coherent potential approximation (CPA) was employed to execute the calculations. The results revealed that native Zr/Ni defects and hydrogen doping have a beneficial effect on the hydrogen storage properties of the studied compounds by decreasing the stability and decomposition temperature. In particular, we find that with an optimal concentration of native Zr/Ni defects and H-doping, the obtained values of the decomposition temperature are in accordance with the required values for the practical use of nickel-metal hydride (Ni-MH) batteries as a negative electrodes (253 to 318 K) as well as powering proton exchange membrane (PEM) fuel cells (289 to 393 K). Using the density of states (DOS), this decrease can be explained by the diminution of the number of Zr and Ni atoms that establish strong bonds with H atoms and by the shift of the total DOS toward the higher energies. The electrochemical capacity of Zr1-x-yNiH3+y and ZrNi1-x-yH3+y compounds increases to reach values of 550 and 540 mAh/g, respectively. These values are almost twice higher compared to the compounds currently used in the market based on the AB5-type alloy LaNi5 (300 mAh/g). These findings of enhanced electrochemical and thermodynamic properties could provide useful clues for the development of better ZrNi-based materials for Ni-MH batte-ries, PEM fuel cells and other related areas.(c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

The limited resources of lithium stimulated the research work to develop new polyanionic cathode materials for sodium-ion batteries. The Na2M22+Fe3+(PO4)(3) (M = Mn, Ni and Co) phases were prepared by autocombustion method assisted by glycine. Structural, morphology, thermal, electrical and electrochemical properties have been investigated. Its structures were determined using Xray powder diffraction and Rietveld method refinements. The two compounds Na2M22+Fe3+(PO4)(3) (M = Mn and Co) are alluaudite-type. Both compounds crystallize in monoclinic system with the space group C2/c and similar parameters: a = 12.0337(3) angstrom, b = 12.6268(3) angstrom, c = 6.5070(1) angstrom, beta = 114.563(2)degrees for Na2M22+Fe3+(PO4)(3) (NMFP) and a = 11.7597(3) angstrom, b = 12.4579(3) angstrom, c = 6.4607(1) angstrom, beta = 113.968(1)degrees for Na2Co2Fe(PO4)(3) (NCFP). The NaNiFe2(PO4)(3) (NNFP) compounds crystallize in orthorhombic system with the space group Imma and unit cell parameters: a = 10.3993(1) angstrom, b= 13.1966(1) angstrom, c = 6.4955(1) angstrom. The composition and morphology of the compounds were checked by energy dispersive spectroscopy coupled with scanning electron microscope. The thermal analysis confirmed the allotropic transition of the three materials from monoclinic to orthorhombic symmetry with the changing of divalent transitions metal ion. The electrical conductivity results of indicated that NNFP has the lowest value of activation energy of value= 0.63 eV owing to the large size of open channels existed in the orthorhombic symmetry. The electrochemical cycling results showed that NMFP cathode delivered the maximum storage capacity of about 94.2 mAh/g which correspond to coloumbic efficiency of about 75.5% after the initial cycling. (C) 2022 Elsevier B.V. All rights reserved.

Langatate (LGT) crystals of La3Ga5.5Ta0 center dot 5O14 composition of diameter 50 mm were grown from the melt by Czochralski technique. Using (1-2 wt %) Ga2O3 excess in the starting charge and growing crystal in mixture argon (0.1-1%O-2) gas atmosphere are a good condition to crystallize LGT under stationary stable regime. The LGT crystals grown along Z-axis exhibit strong faceting. The grown crystals were exempt of inclusions, cracks and secondary phases. The presence of oxygen in the growth chamber is necessary to limit gallium oxide evaporation and strongly affect the crystals coloration and the transmission spectra in the range (200-500 nm). The electrical resistivity is sensitive to the oxygen content in the growth environment.

In the present work, the bonding length, electronic structure, stability, and dehydrogenation properties of the Perovskite-type ZrNiH3 hydride, under different uniaxial/biaxial strains are investigated through ab-initio calculations based on the plane-wave pseudopotential (PW-PP) approach. The findings reveal that the uniaxial/biaxial compressive and tensile strains are responsible for the structural deformation of the ZrNiH3 crystal structure, and its lattice deformation becomes more significant with decreasing or increasing the strain magnitude. Due to the strain energy contribution, the uniaxial/biaxial strain not only lowers the stability of ZrNiH3 but also decreases considerably the dehydrogenation enthalpy and decomposition temperature. Precisely, the formation enthalpy and decomposition temperature are reduced from -67.73 kJ/mol.H2 and 521 K for non-strained ZrNiH3 up to -33.73 kJ/mol.H2 and 259.5 K under maximal biaxial compression strain of epsilon = -6%, and to -50.99 kJ/mol.H2 and 392.23 K for the maximal biaxial tensile strain of epsilon = +6%. The same phenomenon has been also observed for the uniaxial strain, where the formation enthalpy and decomposition temperature are both decreased to -39.36 kJ/mol.H2 and 302.78 K for a maximal uniaxial compressive strain of epsilon = - 12%, and to -51.86 kJ/mol.H2 and 399 K under the maximal uniaxial tensile strain of epsilon = +12%. Moreover, the densities of states analysis suggests that the strain-induced variation in the dehydrogenation and structural properties of ZrNiH3 are strongly related to the Fermi level value of total den- sities of states. These ab-initio calculations demonstrate insightful novel approach into the development of Zr-based intermetallic hydrides for hydrogen storage practical applications. (c) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Cu and Ni substitutions are investigated at spinel MFCO (Manganese Iron Cobalt Oxide) components using a variety of characterization techniques, including XRD, XPS, RAMAN spectroscopy, SEM, TGA, dilatometer measurements, and electrochemical investigations. MnCu0.25Fe0.25Ni0.5CoO4 and MnCu0.5Fe0.25Ni0.25CoO4 spinel oxides were prepared and evaluated as a copper-nickel MFCO protective coating layer on the com-mercially available 316 L stainless steel interconnect for intermediate temperature solid oxide fuel cells (IT-SOFCs). XRD analysis indicates that both powder samples contain a single phase with a cubic structure. In both compounds, mixed Mn3+/Mn4+, Co2+/Co3+, and Cu+/Cu2+ couples are found, showing that co-doping of Ni and Cu into the MFCO spinel resulted in the redistribution of Mn and Co ions (Mn3+, Mn4+, Co2+, and Co3+) into the octahedral sites, which contributed to the increase in electrical conductivity. MnCu0.5Fe0.25Ni0.25CoO4 exhibited a maximum conductivity of 54 S cm-1 at 750 degrees C. Following the area -specific resistance (ASR) of the scale/coating during heating and cooling cycles was used to evaluate the protective action of the coating applied to 316 L stainless steel. Postmortem microstructural analysis of the screen-printed coatings showed good protection against chromium diffusion.

The reaction of the proligand thiosemicarbazido 2-pyrazoline (H2L2), derived from 2,4-pentanedione bis-thiosemicarbazone (H2L1) with Cu(II) and Ni(II) salts, under aerobic conditions, yielded the mononuclear title complexes [M((LO)-O-1)]. The open form of the ligand, H2L1, is oxidized at the central CH2 of the backbone and doubly deprotonated. The obtained complexes were characterized by using single crystal X-ray diffraction, FT-IR and UV-Vis spectroscopic techniques. The structures of the title complexes were determined respectively in monoclinic and triclinic symmetry, where the copper complex [Cu((LO)-O-1)] and nickel complex [Ni((LO)-O-1)] crystallize in the centrosymmetric space groups C2/c and P (1) over bar, respectively. The asymmetric unit is formed of M-II atom occupying a general position, linked by two sulfur and two nitrogen atoms, to form (MS2N2)-S-II square plane environment in both complexes. The crystal structure stabilization of both complexes is ensured by weak interactions hydrogen bonds D-H center dot center dot center dot A with (D = N, C and A = N, O, Sand / or C). This has been confirmed by the three dimensional Hirshfeld surface analysis and the two dimensional fingerprint plots that highlight the dominance of H center dot center dot center dot H, S center dot center dot center dot H/H center dot center dot center dot S and H center dot center dot center dot N/N center dot center dot center dot H intermolecular interactions. The magnetic study revealed that the magnetic chains of Cu and Ni transition metal atoms in square plane environment show two different magnetic interactions in both investigated complexes, with linear and undulating (on zig-zag) metallic chains in Cu and Ni complexes, with antiferromagnetic behaviour for the first complex and ferrimagnetic for the second one.

Substitution of Cu and Ni at spinel MFCO materials is investigated by various characterization techniques such as XRD, XPS, RAMAN spectroscopy, SEM, TGA, dilatometer measurements and electrochemical measurements. MnCu0.25Fe0.25Ni0.5CoO4 and MnCu0.5Fe0.25Ni0.25CoO4 spinel oxides were prepared and evaluated as a copper-nickel MFCO protective coating layer on the commercially available 316L stainless steel interconnect for intermediate temperature solid oxide fuel cells (IT-SOFCs). Single phase of both powder samples with cubic structure are identified using XRD. XPS results confirm that mixed Mn3+/Mn4+, Co2+/Co3+ and Cu+/Cu2+ in couples exist in both compounds, and revealed that co-doping of Ni and Cu into the MFCO spinel resulted in redistribution of Mn and Co ions (Mn3+, Mn4+, Co2+ and Co3+) into the octahedral sites, which increased the electrical conduction by enhanced small polaron hopping and a maximum conductivity of 54 S cm-1 in MnCu0.5Fe0.25Ni0.25CoO4 is achieved at 750 °C. The protective action of the coating applied on 316L stainless steel is evaluated by following the area specific resistance (ASR) of the scale/ coating during heating and cooling cycles. The coating was prepared by screen printing. Post mortem microstructural characterization performed on the both coated samples shows good protection against chromium diffusion.

ZrNi is considered a promising candidate for hydrogen storage and nickel-metal hydride rechargeable batteries (Ni-MH). The effect of creating zirconium and nickel vacancy defects on the dehydrogenation properties of ZrNiH3 is investigated by means of first-principles calculations. The results indicate that nickel vacancy is energetically more favorable to form in ZrNiH3 than zirconium vacancy, because of the lesser formation energy of Ni-vacancy. For both Zr and Ni vacancy defects, the formation enthalpy decreases with increasing the concentration of vacancy and, vice versa. In particular, it is found that with similar to 2.4% of zirconium vacancy defects or with similar to 4.5% of nickel vacancy defects in ZrNiH3, the formation enthalpy is around - 40 kJ/mol.H-2, which is recommended by the U.S. Department of Energy (DOE). It is worth noting also that with slightly higher vacancy defects similar to 2.8 of Zr-vacancy or similar to 5.3% of Ni-vacancy in ZrNiH3, it becomes harder to store hydrogen in these systems without cooling. Moreover, the density of states (DOS) analysis indicates that the stability of ZrNiH3 decreases with increasing Zr-vacancy and Ni-vacancy concentrations, through the shrinkage in the size of the total DOS and shifting in the valence bands near to Fermi level. (C) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Reaction of 2,4-pentanedione with thiosemicarbazide in 1:2 ratio produces cyclic pyrazoline thiosemicarbazone (H2L2 with L-2 = C7H12N6S2). The obtained ligand has been characterized by elemental analysis, UV-Visible, FTIR, H-1 and C-13 NMR. The results suggest that the ligand is in pyrazolinic form, and finally the structure has been confirmed by single crystal X-ray diffraction. The [(L-2(center dot))Cu(SCN)] copper complex has been prepared by reaction of H2L2 and thiocyanate salt with copper acetates and has been fully characterized by single crystal X-ray diffraction, Hirshfeld surface analysis, as well as UV-Visible, FTIR, and Raman spectroscopies. TGA analysis and magnetic measurements were also performed. Single-crystal X-ray diffraction reveals that the complex is a neutral monomer with copper in distorted tetrahedral environment. The anionic ligand (L-2(center dot)) remained in cyclic form and is coordinated as terdentate ligand (SNS). The title complex results from a double deprotonation coupled with a monoelectronic oxidation of H2L2 and it may be seen as a Cu-II-ligand radical type complex. The copper ion is tetra coordinated (CuN2S2) by two sulfur and one nitrogen of (L-2(center dot)) and by thiocyanate nitrogen atoms. The new [(L-2(center dot))Cu(SCN)] complex crystallizes in the monoclinic system and C 2/c space group. Full-Potential Linearized Augmented Planewave Method (FLAPW) calculations based on the Density-Functional Theory (DFT) principle are performed to shed light on both electronic and magnetic structures as well. [(L-2(center dot))Cu(SCN)] showed a greater activity than its parental ligand H2L2 against two strains of the phytopathogenic fungus Verticillium dahliae while a moderate antibacterial activity was recorded with both against Agrobacterium tumefaciens strains and Pseudomonas syringae pv. syringae. (C) 2020 Elsevier Ltd. All rights reserved.

First-principles calculations based on Plane-Wave Self-Consistent Field (PWSCF) method, implemented in quantum espresso program, have been performed on ZrNiH3 substituted with transition metals (V, Ti, Fe, Mn, and Cr). The study aims to investigate the heat of formation in terms of material stability and desorption temperature. It is found that the substitution by transition metals, results in a significant enhancement in the thermodynamic properties accompanied by an increase of the volumetric and gravimetric hydrogen storage capacities. In addition, the obtained values of heat of formation and desorption temperature corroborate with that required by the U.S. Department of Energy (DOE) for stability and volumetric capacity criteria. Moreover, Mn and Fe elements are found to present the lowest substituting content (34%) to obtain optimum hydrogen storage characteristics (enthalpy of formation of - 40 kJ/mol.H-2, decomposition temperature of 300 K and volumetric capacity of 134 g.H-2/l), without affecting the electronic structure and the metallic character of ZrNiH3. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

The novel bi-molybdate beta-Li0.87Na0.13Cr(MoO4)(2) was prepared by solid state reaction route. Single crystal X-ray diffraction experiment revealed that the compound crystallizes in the triclinic system, in P -1 space group with a = 6.715 (2), b = 7.160 (3), c = 7.237 (1) angstrom, alpha = 91.16 degrees (3), beta = 110.59 degrees (2), gamma = 105.54 degrees (3). Its crystal structure is isotypic to LiCr(MoO4)(2) which has interesting magnetic and electrochemical properties [1-3]. Bond valence sum (BVS) and charge distribution (CHARDI) validation tools supported the structural model. The electrical properties were systematically studied by impedance spectroscopy. The ionic conductivity measurements are performed on pellets of 82% and 87% relative density for LiCr(MoO4)(2) and beta-Li0.87Na0.13Cr(MoO4)(2) respectively. AC impedance spectroscopy studies show that the highest overall conductivity is sigma(326 degrees C) = 7.86 x 10(-7) S cm(-1) Probable diffusion pathways of Li+ ions in the both structures were simulated using the bond valence sum BVS maps method. This analysis shows that the ionic transport in these materials is essentially due to simple hopping of Li+ ions parallel to (101) plane. For beta-Li0.87Na0.13Cr(MoO4)(2) compound, the in-situ High Temperature X-Ray Diffraction (HTXRD), in the temperature range from 25 to 650 degrees C, were also performed and Unit-cell thermal expansion has been discussed. The magnetic study show that these compounds present an antiferromagnetic order below the temperatures T-N = 16 and 30 K for LiCr(MoO4)(2) and beta-Li0.87Na0.13Cr(MoO4)(2) respectively. (C) 2020 Elsevier B.V. All rights reserved.

The bis(2,5-di(pyridin-2-yl)-1,3,4-thiadiazole-kappa N-2,N')-bis(thiocyanato-kappa N-1)cobalt(II) complex has been synthetized from the reaction of 2,5-bis(pyridin-2-yl)-1,3,4-thiadiazole (L) with metallic salt CoCl2 center dot 6H(2)O and thiocyanate ion (SCN-) as coligand in H2O/CH3CN at room temperature. The synthetized complex (CoL2(SCN)(2)) has been fully characterized by single crystal X-ray diffraction, Hirshfeld surface analysis, as well as UV-Visible, FTIR, Raman, and NMR spectroscopy. TGA analysis and magnetic measurements were also performed. CoL2(SCN)(2) crystallizes in monoclinic symmetry and P 2(1)/c space group with two independent cobalt crystallographic sites, where each cobalt atom is localized in a distorted octahedral environment CoN6, with the thiadiazole molecules (L) as bidentate ligands in equatorial sites and terminal SCN- ions in axial positions. The crystal cohesion is assured by intermolecular hydrogen bonding, C-H center dot center dot center dot pi; and pi-pi stacking; in addition to the N-Cu coordination bonds. This has been confirmed by the three dimensional Hirshfeld surface analysis and the two dimensional fingerprint plots that highlight the dominance of intermolecular interactions C center dot center dot center dot H/H center dot center dot center dot C and S center dot center dot center dot H/H center dot center dot center dot S. The thermal analysis of CoL2(SCN)(2) reveals that this complex is thermally stable up to 200 degrees C. Variable-temperature magnetic susceptibility measurements on CoL2(SCN)(2) complex indicated an antiferromagnetic exchange between the two nonequivalent cobalt(II) ions with a ferrimagnetic behaviour. (C) 2020 Elsevier B.V. All rights reserved.

The effect of Zr substitution by alkaline earth metals Mg, Be and post-transition metal Al on the evolution of hydrogen storage properties of ZrNiH3 has been investigated by ab-initio calculations based on density functional theory. The stability of the quaternary hydrides is studied by the determination of the formation enthalpy and the desorption temperature. The obtained results indicate a reduction of the formation enthalpy as well as the desorption temperature, hence reflecting the enhancement of hydrogen storage properties of ZrNiH3. Interestingly, each dopant (Mg, Be and Al) achieved its optimum substitution effect at a particular concentration, with Al and Be elements are found to exhibit the lowest substituting content similar to 17% and similar to 23% respectively and Mg with the highest concentration similar to 85%, to achieve an ideal formation enthalpy (Delta H= -40 kJ/mol.H-2) and desorption temperatures (289 to 393 K), as required for practical use of proton exchange membrane fuel cells (PEMFC) without affecting the hydrogen storage capacity as seen in pure ZrNiH3. Moreover, the electronic structure investigated by partial density of states (PDOS), reveals the metallic nature of Zr(1-x)AM(x)NiH(3) (AM = Mg, Be and Al) hydrides.