1313-99-1Relevant articles and documents
Spectral, thermal, and X-ray studies on some new bis and tris-hydrazine and hydrazinium metal pyruvates
Raju,Sivasankar
, p. 371 - 376 (2009)
Some bis-hydrazine metal pyruvates of transition metal ions of the formula M[CH3COCOO]2 [N2H4]2, where M = Co, Ni, Zn or Cd, tris-hydrazine metal pyruvates of the formula M[CH3COCOO]2
K4Ni3O6 and KNa2Ni 2O4, new quasi one-dimensional oxonickelates(II, III)
D Strok Signuris, Katarina,Nuss, Juergen,Jansen, Martin
, p. 2755 - 2760 (2013)
Two new quasi one-dimensional alkali metal oxonickelates, K 4Ni3O6 and KNa2Ni2O 4, were obtained by the azide/nitrate route starting from respective stoichiometric mixtures of KN3, KNO3, NaN3, NaNO3, and NiO. According to the X-ray analyses of the crystal structures [K4Ni3O6: C2/m, Z = 2, a = 899, 53(3), b = 610, 24(2), c = 778.75(2) pm, β = 91.665(2)°, R1 = 0.030, wR2 = 0.088; KNa2Ni2O4: P21/n, Z = 4, a = 573.70(2), b = 1072.89(3), c = 844.93(2) pm, β = 102.916(2)°, R1 = 0.038, wR2 = 0.108], the main feature common to both crystal structures are undulating 1 ∞NiO2 chains consisting of planar, edge-sharing NiO4 squares. The magnetic susceptibilities for both compounds indicate onset of antiferromagnetic ordering at about 5 K. Evaluations of the Curie-Weiss fits result in calculated magnetic moments higher than expected for the respective spin only values, implying some orbital contribution. Below the Neel temperature spin flop or meta-magnetism is observed for both compounds.
Spin-gap formation and thermal structural studies in reduced hybrid layered vanadates
Yan, Bangbo,Luo, Junhua,Dube, Paul,Sefat, Athena S.,Greedan, John E.,Maggard, Paul A.
, p. 5109 - 5118 (2006)
Reduced layered M(C4H4N2)V 4O10 ((I, M = Co; II, M = Ni; III, M = Zn); C 4H4N2 = pyrazine, pyz) hybrid solids were synthesized via hydrothermal reactions at 200-230°C, and their structures determined by single-crystal X-ray diffraction (Cmcm, No. 63, Z = 4; a = 14.311(2), 14.2372(4), 14.425(1) A; b = 6.997(1), 6.9008(2), 6.9702(6) A; and c = 11.4990(8), 11.5102(3), 11.479(1) A; for I, II, and III, respectively). All three solids are isostructural and contain V 4O102- layers condensed from edge- and corner-shared VO5 square pyramids. A single symmetry-unique V atom is reduced by 1/2 electron (on average) and bonds via its apical oxygen atom to interlayer M(pyz)2+ chains. Magnetic susceptibility measurements show a strong temperature dependence and a Curie constant that is consistent with two randomly localized spins per V4O102- formula for III. Further, the unusual discovery of a remarkably well-defined transition to a singlet ground state, as well as formation of a spin gap, is found for III at 22(1) K. The temperature-dependent electrical conductivities show apparent activation energies of 0.36 (I), 0.46 (II), and 0.59 eV (III). During heating cycles in flowing N2, the samples exhibit weight losses corresponding to the removal of predominantly pyrazine, pyrazine fragments, and CO2 via reaction of pyrazine with the vanadate layer. The complete removal of pyrazine without loss of crystallinity is found for well-ground samples of I and III. The SEM images of I and II after heating at 400-500°C show relatively intact crystals, but at 600°C further structural collapse results in the formation of macropores at the surfaces.
Lukic, S. R.,Petrovic, D. M.,Petrovic, A. F.
, p. 1015 - 1022 (1988)
Synthesis, characterization, corrosion inhibition of mild steel in HCl (0.5?N) solution and solid-state electrical conductivity of new Co(II), Ni(II), Cu(II) and Zn(II) complexes
Nassar,Hassan,Elkmash
, (2017)
This work consists of a study of the corrosion-inhibiting and semiconducting properties of new binuclear Co(II), Ni(II), Cu(II) and Zn(II) complexes with a Schiff base, H2L, obtained from the 2:1 M condensation of salicylaldehyde and o-dianisidine, respectively. Elemental, spectral and thermal analyses were used to characterize these complexes. The magnetic susceptibilities of these complexes were also determined. Weight loss, potentiodynamic polarization and scanning optical microscopy were the techniques used to investigate the efficiency of these new compounds as corrosion inhibitors. The antibacterial activity of the compounds was measured against sulfate-reducing bacteria. It was found that inhibition occurs via the chemisorption of metal complexes on the steel surface. This absorption obeys the Langmuir adsorption isotherm model.
Cs2NiO2 revisited. Crystal structure and magnetic properties
Duris, Katarina,Jansen, Martin
, p. 57 - 60 (2012)
Single crystals as well as microcrystalline powders of Cs 2NiO2 were obtained via the azide/nitrate route from appropriate mixtures of CsN3, CsNO3 and NiO. The single-crystal structure analysis confirmed that Cs2NiO2 crystallizes in the tetragonal space group I4/mmm (Z = 2, a = 4.4090(3), c = 13.576(3) A , R1 = 0.036, wR2 = 0.093). Above 45 K, Cs2NiO 2 is paramagnetic, and an analysis based on the Curie-Weiss law has resulted in μ = 2.89 μB paramagnetic units, θ = ?30.8 K and TN ～ 20 K.
Thermal and kinetic study of nickel trifluoromethanesulphonate, trifluoroacetate and acetate
De Souza,Sousa,Paiva,Borges,Melo,Scatena Jr.
, p. 959 - 962 (2008)
The reason of comparing thermal behaviour and kinetics of some nickel compounds, is justified by the influence of anion on it, besides supplying information on the stability of the salts. In this work, Ni(TMS) 2?6H2O, Ni(TFA)2/
Thermal degradation of acetate-intercalated hydroxy double and layered hydroxy salts
Kandare, Everson,Hossenlopp, Jeanne M.
, p. 3766 - 3773 (2006)
Two hydroxy double salts (HDSs), zinc copper hydroxy acetate (ZCA) and zinc nickel hydroxy acetate (ZNA), and an analogous layered compound, zinc hydroxy acetate (ZHA), have been prepared by a coprecipitation method. The thermal degradation of these materials was characterized via thermogravimetric analysis (TGA), differential thermal analysis (DTA), and TGA coupled with Fourier transform infrared spectroscopy of gas-phase products, TGA-FTIR. Loss of physisorbed and interlayer H2O was observed between 50 and 150°C for all compounds. Acetic acid, acetone, water, and CO2 were released at high temperatures with relative acetone yields found to be dependent on precursor identity, with very little formed from ZCA compared with ZHA and ZNA. Combined FTIR and XRD analysis of solid residues extracted at different points in the heating profile suggests that ketonization occurs via dissociative adsorption of acetic acid on ZnO surfaces. Nanometer-sized ZnO particles were formed from ZHA, showing slight preferential growth in the ZnO (002) lattice direction, while the presence of a second metal, Ni or Cu, served to retard ZnO crystallite growth at temperatures below 600°C and eliminate preferential growth. ZCA leads to the formation of reduced copper species (metallic copper and Cu2O) when heated to 250°C.
49 Adsorption des Gaz par les Oxydes Pulverulents. I. Oxyde de Nickel
Teichner,Marcellini,Rué, Et P.
, p. 458 - 471 (1957)
L'oxyde de nickel est obtenu par dissociation de l'hydroxyde de nickel pulvérulent. La cinétique de dissociation dépend de la forme de la nacelle contenant Ni(OH)2. Il est possible de montrer toutefois que cette déshydratation est une réaction topochimique d'ordre 2/3. Les propriétés adsorbantes de NiO obtenu vis-à-vis des gaz donneurs et accepteurs d'electrons sont sensiblement différentes de celles que présente l'oxyde obtenu par oxydation d'un film de nickel. On propose un mécanisme d'adsorption de CO et O2 expliquant l'empoisonnement du catalyseur par le gaz carbonique.
Simple and rapid synthesis of NiO/PPy thin films with improved electrochromic performance
Sonavane,Inamdar,Dalavi,Deshmukh,Patil
, p. 2344 - 2351 (2010)
Nickel oxide/polypyrrole (NiO/PPy) thin films were deposited by a two step process in which the NiO layer was electrodeposited potentiostatically from an aqueous solution of NiCl2·6H2O at pH 7.5 on fluorine doped tin oxide (FTO) coated conducting glass substrates, followed by the deposition of polypyrrole (PPy) thin films by chemical bath deposition (CBD) from pyrrole mixed with ammonium persulfate (APS). The NiO/PPy films were further characterized for their structural, optical, morphological and electrochromic properties. X-ray diffraction study indicates that the films composed of polycrystalline NiO and amorphous PPy. Infrared transmission spectrum reveals chemical bonding between NiO and PPy. Rectangular faceted grains were observed from scanning electron microscopy results. The electrochromic (EC) property of the film was studied using cyclic voltammogram (CV), chronoamperometry (CA) and optical modulation. The NiO/PPy presents superior EC properties than their individual counterparts. The coloration/bleaching kinetics (response time of few ms) and coloration efficiency (358 cm2/C) were found to be improved appreciably. The dramatic improvement in electrochemical stability (from about 500 c/b cycles for PPy to 10,000 c/b cycles for NiO/PPy) was observed. This work therefore demonstrates a cost-effective and simple way of depositing highly efficient, faster and stable NiO/PPy electrodes for EC devices.
Synthesis, structure analysis and thermodynamics of [Ni(H 2O)4(TO)2](NO3)2· 2H2O (TO = 1,2,4-triazole-5-one)
Chen, San-Ping,Li, Na,Wei, Qing,Gao, Sheng-Li
, p. 1115 - 1120 (2010)
A novel complex [Ni(H2O)4(TO)2](NO3) 2· 2H2O (TO = 1,2,4-triazole-5-one) was synthesized and structurally characterized by X-ray crystal diffraction analysis. The decomposition reaction kinetic of the complex was studied using TG-DTG. A multiple heating rate method was utilized to determine the apparent activation energy (Ea) and pre-exponential constant (A) of the former two decomposition stages, and the values are 109.2 kJ mol-1, 10 13.80 s-1; 108 0 kJ mol-1, 1023.23 s-1, respectively The critical temperature of thermal explosion, the entropy of activation (ΔS≠), enthalpy of activation (ΔH≠) and the free energy of activation (ΔG ≠) of the initial two decomposition stages of the complex were also calculated. The standard enthalpy of formation of the new complex was determined as being-1464.55 ± 1.70 kJ mol-1 by a rotating-bomb calorimeter. Akademiai Kiado, Budapest, Hungary 2010.
Oxygen non-stoichiometry and reducibility of B-site substituted lanthanum manganites
Patcas,Buciuman,Zsako
, p. 71 - 76 (2000)
LaMn0.8B'0.2O3+(δ) (B'=Ni, Zn, Cu) and LaMn0.5Cu0.5O3+(δ) perovskites were studied by temperature programmed reduction (TPR). Oxygen non-stoichiometry of the perovskite samples calcined in
Synthesis, characterization, and catalytic performance of La1-xCexNi1-yZryO3 perovskite nanocatalysts in dry reforming of methane
Dezvareha, Parastoo,Aghabozorgb, Hamidreza,Hossaini Sadrc, Moayad,Zared, Karim
, p. 1469 - 1477 (2018)
La1-xCexNi1-yZryO3 perovskite nanocatalysts were prepared by a method called citrate sol-gel. The samples were studied by the methods as X-ray diffraction (XRD), temperature programmed reduction (TPR), and inductively coupled plasma (ICP) technique.The BET method was used to determine the specific surface area. In addition, scanning and transmission electron microscopy techniques were employed to study the morphology of the prepared samples31. The XRD patterns confirmed the formation of perovskite with well-crystallized structure in doping level up to x= 0.1 and y= 0.2. The results of morphology studies revealed that homogenous particles in nanometer range were achieved. Based on the TPR analysis, reduction process occurred at higher temperatures and became difficult as the doping level of Zr increases. The catalytic performance was studied in dry reforming of methane (DRM) with CO2. The catalyst La0.9Ce0.1Ni0.8Zr0.2O3 perovskite provides the highest catalytic performance. CH4 conversion was more than 60%, CO2 conversion was more than70% and the H2/CO molar ratio was ~1, respectively. Catalytic activity of La1-xCexNi1-yZryO3 nanocatalysts was enhanced when the doping level of Zr (y) increased up to 0.2, and the following result was obtained for H2/CO ratio: LaNiO3 > La0.9Ce0.1Ni0.8Zr0.2O3 > La0.9Ce0.1Ni0.9Zr0.1O3 > La0.9Ce0.1Ni O3
The synergistic influences of OH- concentration and electrolyte conductivity on the redox behavior of Ni (OH) 2 /NiOOH
Hu, Chi-Chang,Chang, Kuo-Hsin,Hsu, Tung-Yu
, p. F196-F200 (2008)
The synergistic influences of the OH- concentration and electrolyte conductivity on the redox behavior of NiOOH/Ni (OH) 2 for nickel oxide-coated graphite electrodes are clearly demonstrated by voltammetric and impedance analyses. The increase in the OH-
Morphological and pharmacological investigation on some biopotent materials derived from substituted pyrimidine and imidazole enzyme constituents
Shobana, Sutha,Subramaniam, Perumal,Dharmaraja, Jeyapraksh,Narayan, Arvind
, p. 242 - 253 (2014)
Coordinating behavior of novel N2O type mixed ligand complexes (1-6) have been synthesized from substituted fluoropyrimidine [5-Fluorouracil (5-FU; A)] with biopotent imidazole enzyme constituents (B) viz., imidazole(him) and benzimidazole(bim) in the presence of Ni(II), Cu(II) and Zn(II) ions. Synthesized complexes were characterized by chemical analysis, spectral studies, magnetic moment and conductivity measurements. The results of chemical analysis and the observed low molar conductance values propose their stoichiometry to be 1:1:1 (M:A:B) with non-electrolytic nature. From the spectral data, it is inferred that the ligands A & B coordinate with M(II) ions in bi and monodentate approach through C(4)O, N(3) and imidazole ring N(3) atoms respectively. The thermogravimetric analysis shows the dehydration, decomposition and thermal stability of mixed ligand complexes. XRD and SEM patterns show sharp crystalline peaks with homogeneous morphology. In vitro antimicrobial activities of free ligands (A & B) and their metal complexes were screened against some pathogenic strains by well diffusion technique. Absorption and gel electrophoresis experiments on the interaction of mixed ligand complexes with DNA suggest that all the complexes can bind as well as cleave the DNA by intercalation between chromophores and DNA base pairs. In addition, in vitro antioxidant activities were tested by DPPH free radical scavenging model.
Unprecedented interweaving of hetero-chiral single helical chains into a 3D chiral framework with (10, 3) topology
Zhang, Cui-Qiao,Fu, Feng,Li, Dong-Sheng,Ren, Yi-Xia,Zhao, Xin-Ze
, p. 652 - 656 (2008)
The title compound, [Ni(dcbp)(H2O)2](H2dcbp = 2,2′ -bipyridine-4,4′ -dicarboxy acid), was synthesized under hydrothermal conditions. The structure was determined by single-crystal X-ray diffraction and further characterized by elemental analysis, IR, and TGA. The compound crystallized in an orthorhombic system, P212121 space group, a = 6.7665(7) A, b = 12.9047(14) A, c = 13.1848(15) A, β = 90°. In the compound, each Ni(II) atom exhibits a six-coordinated distorted octahedral geometry. Interestingly, carboxylate group from dcbp ligands bridges between adjacent Ni(II) atoms giving rise to unprecedented interweaving of hetero-chiral single helical chains into a 3D chiral (10, 3) framework. Copyright Taylor & Francis Group, LLC.
Exfoliation-free nanosheet synthesis of transition-metal hydroxynitrate and its transformation to oxide particulate nanosheet
Cui, Hongtao,Zayat, Marcos,Levy, David
, p. 144 - 145 (2007)
A new strategy, epoxide-assisted precipitation route presented in this work, allows the exfoliation-free nanosheet synthesis of Ni3(NO 3)2(OH)4 by the control of dynamics of the precipitation reaction. The mechanism of growth limitation in the third direction can be explained by the bonding of the molecule resulting from the ring-opening reaction of the epoxide to the surface of primary nanosheets, preventing the thickening of the layer. Copyright
Diefallah, El-H. M.,Basahl, S. N.,El-Fass, M. M.,Al-Sabban, E. A.
, p. 141 - 150 (1991)
Hydrothermal synthesis, crystal structures, and properties of CoII and NiII supramolecular complexes with 2,4,6-trimethyl benzoate and 4,4′-bipyridyl
Indrani, Murugan,Ramasubramanian, Ramasamy,Kumaresan, Sudalaiandi,Kang, Sung Kwon,Chen, Min,Du, Miao
, p. 3593 - 3600 (2008)
Two new coordination complexes, viz. [Co(tmb)2(4,4′-bpy)2(H2O)2](Htmb)2 (1) and {[Ni(tmb)2(μ-4,4′-bpy)2(H2O)2](4,4′-bpy)}n (2), have been hydrothermally synthesized by reaction of the corresponding metal acetate with 2,4,6-trimethylbenzoic acid (Htmb) and 4,4′-bipyridyl (4,4′-bpy). X-ray single-crystal diffraction suggests that complex 1 represents a discrete mononuclear species in which the central metal ion is coordinated by the terminal carboxylate moiety and the 4,4′-bipyridyl ligand. The crystal structure of complex 2 reveals a 1D chain coordination polymer in which the Ni(II) ions are connected by the bridging 4,4′-bipyridyl ligands. In both cases, the coordination arrays are further extended via hydrogen bonding interactions to generate 3D supramolecular networks. Complexes 1 and 2 have also been characterized by spectroscopic (IR and UV/Vis), thermal (TGA) and magnetic susceptibility measurements. In addition, both complexes exhibit antimicrobial activity.
Thermal, spectral and magnetic behaviour of 2,3,4-trimethoxybenzoates of Mn(II), Co(II), Ni(II) and Cu(II)
Ferenc, Wieslawa,Bocian, Beata,Sarzynski
, p. 377 - 383 (2006)
Four new complexes of 2,3,4-trimethoxybenzoic acid anion with manganese(II), cobalt(II), nickel(II) and copper(II) cations were synthesized, analysed and characterized by standard chemical and physical methods. 2,3,4-Trimethoxybenzoates of Mn(II), Co(II), Ni(II) and Cu(II) are polycrystalline compounds with colours typical for M(II) ions. The carboxylate group in the anhydrous complexes of Mn(II), Co(II) and Ni(II) is monodentate and in that of Cu(II) monohydrate is bidentate bridging one. The anhydrous complexes of Mn(II), Co(II) and Ni(II) heated in air to 1273 K are stable up to 505-517 K. Next in the range of 505-1205 K they decompose to the following oxides: Mn3O4, CoO, NiO. The complex of Cu(II) is stable up to 390 K, and next in the range of 390-443 K it loses one molecule of water. The final product of its decomposition is CuO. The solubility in water at 293 K is of the order of 10-3 mol dm-3 for the Mn(II) complex and 10-4 mol dm-3 for Co(II), Ni(II) and Cu(II) complexes. The magnetic moment values of Mn2+, Co2+, Ni2+ and Cu2+ ions in 2,3,4-trimethoxybenzoates experimentally determined in the range of 77-300 K change from 5.64-6.57 μB (for Mn 2+), 4.73-5.17 μB (for Co2+), 3.26-3.35 μB (for Ni2+) and 0.27-1.42 μB (for Cu2+). 2,3,4-Trimethoxybenzoates of Mn(II), Co(II) and Ni(II) follow the Curie-Weiss law, whereas that of Cu(II) forms a dimer.
Kinetic and thermodynamics studies on the decompositions of Ni3C in different atmospheres
Leng, Yonghua,Xie, Lei,Liao, Fuhui,Zheng, Jie,Li, Xingguo
, p. 14 - 18 (2008)
The thermal decompositions (including TG and DSC) of nickel carbide were studied under different atmospheres of Ar, air and H2. X-ray diffraction combined with element analysis indicated that nickel metal, together with solid amorphous carbon,
A series of bis(pyridyl)-bis(amide)-modulated metal-1,2-phenylenediacetate coordination polymers: construction and selective dye adsorption
Wang, Xiuli,Zhao, Jing,Le, Mao,Lin, Hongyan,Liu, Guocheng,Wang, Xiang
, p. 9316 - 9324 (2016)
Five new coordination polymers (CPs), namely, [Cu(3-bpcb)(1,2-pda)]·2H2O (1), [Cu(4-bpah)(1,2-pda)(H2O)]·H2O (2), [Ni2(4-bpah)2(1,2-pda)2(μ2-H2O)] (3), [Cu3(4-bpfp)(1,2-pda)2(μ3-OH)2] (4), [Co(4-bpfp)0.5(1,2-pda)(H2O)] (5), were prepared by hydrothermal reactions of metal(ii) chloride with 1,2-H2pda (H2pda = 1,2-phenylenediacetic acid) in the presence of different bis(pyridyl)-bis(amide) ligands (3-bpcb = N,N′-bis(3-pyridinecarboxamide)-1,4-benzene; 4-bpah = N,N′-bis(4-pyridinecarboxamide)-1,2-cyclohexane; and 4-bpfp = N,N′-bis(4-pyridylformyl)piperazine) and structurally characterized by single crystal X-ray diffraction, infrared spectroscopy (IR), elemental analysis, powder X-ray diffraction (PXRD) and thermogravimetric analysis (TGA). Complexes 1-3 show three different 2D layers with diverse (42·67·8)(42·6), (44·62) and (42·6)(42·67·8) topological structures, respectively. Complex 4 exhibits a 3D polymeric framework, which presents a novel (3,4,8)-connected topology with the Schl?fli symbol (3·4·5)2(32·42·52·614·74·83·9)(32·63·7). Complex 5 displays a 3D network with 3,4-connected (42·63·8)(42·6) topology. The diverse arrangements of these complexes show the remarkable sensitivity of the metal(ii)-H2pda system to the different bis(pyridyl)-bis(amide) ligands. In addition, the electrochemical properties of complexes 3-5 and the dye adsorption properties of the title complexes are also discussed.
1D hydrogen-bonded infinite chains from tetraaza macrocycle nickel(II) complexes and ligands
Lim, In-Taek,Choi, Ki-Young
, p. 361 - 368 (2017)
The reaction of square planar complex [Ni(L2)]Cl2·2H2O (L2?=?3,14-diethyl-2,6,13,17-tetraazatricyclo[14,4,01.18,07.12]docosane) with ligands KNCS and H2cpdc generates 1D hydrogen-bonded infinite chains [Ni(L2)(NCS)2] (1) and [Ni(L2)(H-cpdc)2] (2) (H2cpdc?=?cyclopropanedicarboxylic acid). These compounds have been characterized by X-ray crystallography, spectroscopic, cyclic voltammetry and thermogravimetry. The crystal structures of compounds 1 and 2 show that each nickel(II) centre has an elongated distorted octahedral geometry with the axial ligands. Electronic spectra and redox potentials of the complexes 1 and 2 exhibit a high-spin octahedral environment, which is reflected by the nature of the axial ligands. The TGA behaviors of two compounds 1 and 2 are also significantly affected by the nature of the axial ligands.
Nb effect in the nickel oxide-catalyzed low-temperature oxidative dehydrogenation of ethane
Zhu, Haibo,Ould-Chikh, Samy,Anjum, Dalaver H.,Sun, Miao,Biausque, Gregory,Basset, Jean-Marie,Caps, Valerie
, p. 292 - 303 (2012)
A method for the preparation of NiO and Nb-NiO nanocomposites is developed, based on the slow oxidation of a nickel-rich Nb-Ni gel obtained in citric acid. The resulting materials have higher surface areas than those obtained by the classical evaporation method from nickel nitrate and ammonium niobium oxalate. These consist in NiO nanocrystallites (7-13 nm) associated, at Nb contents >3 at.%., with an amorphous thin layer (1-2 nm) of a niobium-rich mixed oxide with a structure similar to that of NiNb2O6. Unlike bulk nickel oxides, the activity of these nanooxides for low-temperature ethane oxidative dehydrogenation (ODH) has been related to their redox properties. In addition to limiting the size of NiO crystallites, the presence of the Nb-rich phase also inhibits NiO reducibility. At Nb content >5 at.%, Nb-NiO composites are thus less active for ethane ODH but more selective, indicating that the Nb-rich phase probably covers part of the unselective, non-stoichiometric, active oxygen species of NiO. This geometric effect is supported by high-resolution transmission electron microscopy observations. The close interaction between NiO and the thin Nb-rich mixed oxide layer, combined with possible restructuration of the nanocomposite under ODH conditions, leads to significant catalyst deactivation at high Nb loadings. Hence, the most efficient ODH catalysts obtained by this method are those containing 3-4 at.% Nb, which combine high activity, selectivity, and stability. The impact of the preparation method on the structural and catalytic properties of Nb-NiO nanocomposites suggests that further improvement in NiO-catalyzed ethane ODH can be expected upon optimization of the catalyst.
HSAB principle and nickel(II) ion reactivity towards 1-methyhydantoin
Puszyńska-Tuszkanow, Mariola,Daszkiewicz, Marek,Maciejewska, Gabriela,Staszak, Zbigniew,Wietrzyk, Joanna,Filip, Beata,Cie?lak-Golonka, Maria
, p. 2016 - 2025 (2011)
1-Methylhydantoin and its novel nickel(II) complex [Ni(H2O) 4(1-mhyd)2] were prepared and identified, by elemental analysis, single crystal X-ray determination and MS methods. In addition, the complex was characterized by spectroscopic (IR, UV-Vis), magnetic and thermal techniques. The ligand reveals an interesting supramolecular architecture with both classical and non-conventional extended HB bonding networks. All rings and chains formed due to this HB bonding are embedded into the undulated pattern. A single crystal X-ray diffraction analysis of the complex shows that the nickel ion is coordinated by deprotonated hydantoin and water ligands in a N 2O4 tetragonal arrangement. In the [Ni(H 2O)4(1-mhyd)2] structure both inter and intramolecular hydrogen bonds are created with the participation of water molecules. The ESI-MS method confirmed mono-nuclearity of the complex while electronic spectroscopy proved the tetragonal and pseudooctahedral geometries around the metal ion in the solid state and solution, respectively. By application of the "average environment rule", 10Dq parameters were obtained for the hypothetical, hexa-coordinate [Ni(1-mhyd)6] approximation or rather more realistic [Ni(1-mhyd)3] chelate. Based on this the mhyd ligand was ranked in the spectrochemical series close to ammonia. The general consideration of the structure of the hydantoin complexes as a function of the metal ion hardness within the framework of the HSAB theory has been provided. Both the ligand and the complex were found to be non-toxic agents against breast (MCF-7), lung carcinoma epithelial (A549) and mouse fibroblasts (Balb/3T3) cancer cell lines.
Interfacial Electron Redistribution of Hydrangea-like NiO@Ni2P Heterogeneous Microspheres with Dual-Phase Synergy for High-Performance Lithium–Oxygen Battery
Li, Runjing,Ran, Zhiqun,Shu, Chaozhu,Wen, Xiaojuan,Xu, HaoYang,Yan, Yu,Zeng, Ting,Zhao, Chuan
, (2022/01/19)
Lithium–oxygen batteries (LOBs) with ultra-high theoretical energy density (≈3500?Wh?kg?1) are considered as the most promising energy storage systems. However, the sluggish kinetics during the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) can induce large voltage hysteresis, inferior roundtrip efficiency and unsatisfactory cyclic stability. Herein, hydrangea-like NiO@Ni2P heterogeneous microspheres are elaborately designed as high-efficiency oxygen electrodes for LOBs. Benefitting from the interfacial electron redistribution on NiO@Ni2P heterostructure, the electronic structure can be modulated to ameliorate the chemisorption of the intermediates, which is confirmed by density functional theory (DFT) calculations and experimental characterizations. In addition, the interpenetration of the P-O bond at the NiO@Ni2P heterointerface leads to the internal doping effect, thereby boosting electron transfer to further improve ORR and OER activities. As a result, the NiO@Ni2P electrode shows a low overpotential of only 0.69?V, high specific capacity of 18254.1?mA?h?g?1 and superior long-term cycling stability of over 1400 h. The exploration of novel bifunctional electrocatalyst in this work provides a new solution for the practical application of LOBs.
Synthesis, characterization, in vitro antimicrobial and cytotoxic evaluation of Co(II), Ni(II), Cu(II) and Zn(II) complexes derived from bidentate hydrazones
Devi, Jai,Kumar, Sanjeev,Kumar, Deepak,Jindal, Deepak Kumar,Poornachandra
, p. 423 - 455 (2021/11/03)
Co(II), Ni(II), Cu(II) and Zn(II) complexes have been synthesized from hydrazone ligands (HL1–HL4) obtained by condensation reaction of 6-chlorothiochroman-4-one with benz hydrazide/nicotinic hydrazide/isonicotinic hydrazide/p-toluic
Antibacterial and anticorrosion behavior of bioactive complexes of selected transition metal ions with new 2-acetylpyridine Schiff base
Ashmawy, Ashraf M.,Deghadi, Reem G.,Elsharkawy, Ahmed E.,Mohamed, Gehad G.
, (2022/01/19)
Successful preparation of Schiff base 4-(4-aminophenoxy)-N-(1-(pyridin-2-yl)ethylidene)aniline derived from refluxing of 4,4-oxydianniline with 2-acetylpyridine within 2?h in 1:1 molar ratio was performed. Different transition metal complexes were synthesized by reacting metal chlorides with the formed ligand in 1:1 molar ratio. Structural features of the complexes were obtained from different tools such as infrared (IR), 1H-nuclear magnetic resonance (1H-NMR), ultraviolet–visible (UV-vis), molar conductivity, thermogravimetric (TG)/differential thermogravimetric (DTG), microanalysis, and mass spectrometry. All complexes had an octahedral structure and Schiff base acted as a neutral bidentate ligand that linked to metal centers via N-azomethine and N-pyridine atoms. Cr(III), Fe(III), and Ni(II) complexes were electrolytes while other complexes were nonelectrolytes. The molecular structure of Schiff base was optimized theoretically and its HOMO and LUMO energies were dictated by B3LYP/DFT calculations. The in vitro antibacterial activity versus some selected bacteria species showed that all prepared compounds were biologically active except Fe(III) complex against certain species and Co(II) complex had the highest biological activity values. Molecular docking was used to determine effective binding modes between ligand and its [Co(L)(H2O)2Cl2]·4H2O complex with active sites of 4WJ3, 4ME7, 4K3V, and 3T88 receptors. The strongest binding of Co(II) complex was with the 4ME7 receptor with lowest binding energy value ?25.4?kcal mol?1. Schiff base as corrosion inhibitors for mild steel in 1.0-M HCl had been investigated using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PP), and electrochemical frequency modulation (EFM). The results showed that the inhibitor acts as a mixed-type inhibitor. The inhibition efficiency increases with increasing inhibitor concentration to its maximum of 97.5% at 1?×?10?3?M solution. The adsorption model obeys the Langmuir isotherm, and Gibbs free energy was around ?40 kJ/mol, indicating that it is spontaneously and chemically adsorbed on the surface. SEM/EDX results proved the sticking of a barrier film on the mild steel sample.
