Characterization Of Nickel Research Articles

Characterization of Nickel Induced Crystallized Silicon by Spectroscopic Ellipsometry

AbstractIn this work Spectroscopic Ellipsometry (SE) was used to study metal induced crystallization (MIC) on amorphous silicon films in order to analyze the influence of different annealing conditions on their structural properties. The variation of the metal thickness has shown to be determinant on the time needed to full crystallize silicon films. Films of 100 nm thickness crystallize after 2h at 500°C using 1 nm of Ni deposited on it. When reducing the average metal thickness down to 0.05 nm the same silicon film will need almost 10 hours to be totally crystallized. Using a new approach on the modelling procedure of the SE data we show to be possible to determine the Ni remaining inside the crystallized films. The method consists in using Ni as reference on the Bruggeman Effective Medium Approximation (BEMA) layer that will simulated the optical response of the crystallized silicon. Silicon samples and metal layers with different thicknesses were analyzed and this new method has shown to be sensible to changes on the initial metal/silicon ratio. The nickel distribution inside the silicon layers was independently measured by Rutherford Backscattering Spectroscopy (RBS) to check the data obtained from the proposed approach.

Rearrangement of phosphinohydrazide ligand –NPh-N(PPh 2) 2 in transition metal coordination sphere: Synthesis and characterization of nickel and cobalt spirocyclic complexes M(NPh-PPh 2[dbnd]N-PPh 2) 2 and their properties

The reaction of diphosphinohydrazine PhNH-N(PPh 2) 2 ( 1) with cobalt(II) silylamide, Co[N(SiMe 3) 2] 2, proceeds via formation of unstable phosphinohydrazide complex Co[NPh-N(PPh 2) 2] 2 followed by rearrangement to a new chelating compound Co(NPh-PPh 2 N-PPh 2) 2 ( 2). Disproportionation of nickel(I) silylamide, (Ph 3P) 2Ni-N(SiMe 3) 2, in the presence of 1, yields Ni(0) and Ni(II) phosphinoamide complexes: Ni[(Ph 2P) 2N-NPhH] 2 ( 3), Ni(NPh-PPh 2 N-PPh 2) 2 ( 4). X-ray analysis reveals tetrahedral environment of the cobalt atom in 2 and square-planar environment of the nickel atom in cis- 4. In contrast to the crystalline patterns, the solutions of 2 in THF or toluene have EPR signal which is typical to square-planar low-spin d 7 cobalt complex. The reactions of 2 with dioxygen, elemental sulfur and diphenyldiazomethane led to the spirocyclic insertion products Co(NPh-PPh 2 N-PPh 2 X) 2 (X = O, S, NNCPh 2) while the absorption of carbon monoxide is reversible.

Electrochemical Synthesis and Characterization of Nickel(II) Complexes with N-2-Pyridyl-sulfonamide Ligands

Heteroleptic nickel(II) complexes [NiL2L′] of a series of monoanionic and potentially bidentate N-2-pyridyl-sulfonamide ligands [HL] and 2,2′-bipyridine or 1,10-Phenanthroline (L′) have been prepared by electrochemical oxidation of a nickel anode in an acetonitrile solution of the ligands. The complexes have been characterized by microanalysis, IR and electronic spectroscopy, magnetic measurements and LSI mass spectrometry. The crystal structure of [Ni(Ms6mepy)2(bipy)] has been determined by x-ray diffraction and shows the metal in an octahedral NiN6 environment. Octahedral structures are also proposed for the other complexes with the N-2-pyridyl-sulfonamide ligands acting as N,N′ or N, O bidentate systems, depending on the position of the methyl substituent on the pyridine ring.

Characterisation of nickel based hardfacing deposits on austenitic stainless steel

Nickel based hardfacing alloys Colmonoy-5 and Colmonoy-6 deposited on type 316L austenitic stainless steel substrate using the gas tungsten arc welding process, were characterised for their microstructure and hardness variations across the deposit/substrate interface, and for identification of the principal precipitates present in these hardface deposits. Hardness measurements and electron probe microanalysis (EPMA) across the interface revealed the presence of a dilution zone 2·5 mm wide in the Colmonoy-6 deposit and 1·5 mm wide in the Colmonoy-5 deposit. EPMA and X-ray diffraction studies of the precipitates showed that he blocky type precipitates were chromium borides and the needle-like precipitates were chromium carbides. Also, stress relief heat treatment at 1123 K for 4 h was found to have no significant effect on the hardness of these hard face deposits.

Synthesis and Characterization of Nickel(II) Complexes with 18-Membered Decaaza Macrocycles 1,10-dialkyl-5,6,14,15-tetraphenyl-1,3,4,7,8,10,12,13,16,17-decaazacyclooctadecane

Six new square-planar nickel(II) complexes of 18-membered decaaza macrocyclic ligands 5,6,14,15-tetraphenyl-1,3,4,7,8,10,12,13,16,17-decaazacyclooctadecane [Ni((phenyl)4 [18] ane N10)](ClO4)2 (1); 1,10-dimethyl- [Ni(Me2 (phenyl)4 [18] ane N10)](ClO4)2 (2); 1,10-diethyl- [Ni(Et2 (phenyl)4 [18] ane N10)](ClO4)2 (3); 1,10-dipropyl-[Ni(Pr2 (phenyl)4 [18] ane N10)](ClO4)2 (4); 1,10-dibutyliso- [Ni(Bu2 (phenyl)4 [18] ane N10)](ClO4)2 (5); 1,10-dibenzyl-5,6,14,15-tetraphenyl-1,3,4,7,8,10,12,13,16,17-decaazacylooctadecane [Ni((Benzyl)2 (phenyl)4 [18] ane N10)](ClO4)2 (6); [Ni((phenyl)4 [18] ane N10)(NCS)2] (7); [Ni(Me2 (phenyl)4 [18] ane N10)(NCS)2] (8); [Ni(Et2 (phenyl)4 [18] ane N10)(NCS)2] (9); [Ni(Pr2 (phenyl)4 [18] ane N10)(NCS)2] (10); [Ni(Bu2 (phenyl)4 [18] ane N10)(NCS)2] (11) and [Ni(Benzyl)2 (phenyl)4 [18] ane N10)(NCS)2] (12) have been prepared from the one-pot template condensation reaction of formaldehyde, benzildihydrazone with alkyl and benzyl amine in the presence of nickel(II) ion. Elemental analyses, IR, UV-VIS spectroscopy, conductometric and magnetic measurements have been used to characterize the nickel(II) complexes of these decaaza macrocycles. The spectra of [Ni(R2 (phenyl)4 [18] ane N10)](ClO4)2 shows that the four nitrogen (α-diimine) atoms are coordinated to the nickel(II) ion. The hydrazones of the (α-diimine) function have the anti-anti configuration yielding a macrocyclic species with D2 h symmetry. The nickel(II) complexes are diamagnetic and four coordinates exhibit only weak interactions with different solvents. The physical and chemical properties of the complexes are compared with other closely related complexes.

Synthesis and characterization of nickel and palladium complexes containing hetero-multidentate PNO ligands

Formation of mono- and dinuclear complexes containing ligands stemmed from the condensation of 2,6-diformyl-4-methylphenol derivatives with 2-(diphenylphosphino)aniline ( P∼ N) was investigated. Condensation of P∼ N with 2,6-diformyl-4-methylanisole yielded the desired bis(imine-phosphine) L 3 , but provided the cyclized benzoazaphospholium compound with 2,6-diformyl-4-methylphenol. Complexation of L 3 with (COD)PdCl 2 gave the dinuclear complex 4. On the other hand, L 3 underwent the intramolecular cyclization in the presence of (DME)NiCl 2 via the formation of benzoazaphospholium rings. Template condensation of 2,6-diformyl-4-methylphenol with P∼ N in the presence of metal ions yielded the mononuclear nickel(II) and palladium(II) complexes, respectively.

Hydrothermal synthesis and characterization of nickel and cobalt sulfides nanocrystallines

Novel sea-urchinlike nanocrystallines of hexagonal α-NiS, rhombohedral β-NiS, and cubic phase Co 9S 8 have been successfully synthesized via a facile hydrothermal synthetic route from the thiourea and hydrated metal chloride in hydrazine hydrate solution under mild conditions. The morphology and structure of the final products were investigated in detail by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and selected area electron diffraction (SAED). TEM and SEM show the formation process of the metal sulfides, and the probable formation mechanism of the sea-urchinlike nickel and cobalt sulfides nanocrystallines was discussed on the basis of the experimental results.

Partial Oxidation of Methane to Synthesis Gas over Oxidized Diamond Supported Catalysts—Catalytic Behavior of Nickel and Cobalt Species—

Characterization of nickel and cobalt catalysts supported on oxidized diamond (O-dia) in the partial oxidation of methane to synthesis gas was carried out by X-ray photoelectron spectroscopy (XPS) and the transient response pulse technique. Carbon deposition occurred on nickel/O-dia, but not on cobalt/O-dia catalyst at 873 K throughout prolonged reaction. XPS analyses observed partially reduced nickel oxides on nickel/O-dia catalyst after reaction with methane/oxygen (5/1) at 873 K. Co(0), partially reduced cobalt oxide, and Co(III) oxide phases were found on cobalt/O-dia catalyst after reaction at 873 K. Transient response methane/oxygen (2/1) pulse studies found a large amount of hydrogen production occurred immediately at 873 K over the nickel/O-dia catalyst. However, a very small amount of hydrogen production was seen over the cobalt/O-dia catalyst, indicating that nickel and cobalt species supported on O-dia exhibited different behavior. Transient response of the catalyst bed temperature found that endothermic reaction occurred on the nickel/O-dia catalyst at 873 K, but exothermic reaction proceeded on the cobalt/O-dia catalyst. These results suggest that methane decomposition to hydrogen is the primary reaction path over nickel/O-dia catalyst, whereas complete oxidation is the primary reaction followed by steam and carbon dioxide reforming to produce synthesis gas over the cobalt/O-dia catalyst.

Synthesis and characterization of nickel(II) and copper(II) complexes of some large-ring macrocycles derived from diethylenetriamine

Diethylenetriamine condenses with carbon tetrachloride, tetrachloroethylene, 1,1,2,2-tetrachloroethane, chloroform and dichloromethane in the presence of nickel(II) ions to produce macrocyclic hexaaza ligands, 1,4.7,9,12,15-hexaaza-8,8,16,16,-tetrachlorocyclohexadecane (HTCH), 1,4,7,10,13,16-hexaaza-8,9,17,18-tetrachlorocyclooctadeca-8,17-diene (HTOD), 1,4,7,10,13,16-hexaaza-8,9,17,18-tetrachlorocyclooctadecane (HTCO), 8,16-dichloro-1,4,7,9,12,15-hexaazacyclohexadecane (DHCH) and 1,4,7,9,12,15-hexaazacyclohexadecane (HACH), respectively. But, the template condensation of diethlenetriamine and chloroform in presence of copper(II) ions yields a cage-macrocycle, 2,5,8,10,13,16,17,20,23-nonaazabicyclo[7.7.7]tricosane (NACT). A blue condensed product of diethylenetriamine, dichloromethane and copper(II) ion could not be crystallized from the reaction mixture. The isolated complexes [Ni 2 (HTCH)(H 2 O) 6 ]Cl 4 .7H 2 O, [Ni 2 (HTOD)(H 2 O) 6 ]Cl 4 , [Ni 2 (HTCO)(H 2 O) 6 ]Cl 4 , [Ni 2 (DHCH)(H 2 O) 6 ]Cl 4 .13H 2 O, [Ni 2 (HACH)-(H 2 O) 6 ]Cl 4 .10H 2 O and [Cu 3 (NACT)(H 2 O) 3 ]Cl 6 , and the metal-free ligand NACT.9HCl have been characterized by elemental analyses, conductivity measurements, melting point and spectroscopic studies.

Monolithic nickel(II)-based aerogels using an organic epoxide: the importance of the counterion

The synthesis and characterization of nickel(II)-based aerogel materials prepared using the epoxide addition method is described. The addition of the organic epoxide propylene oxide to an ethanolic solution of NiCl2·6H2O resulted in the formation of an opaque light green monolithic gel and subsequent drying with supercritical CO2 gave a monolithic aerogel material of the same color. This material has been characterized using powder X-ray diffraction, electron microscopy, elemental analysis, and nitrogen adsorption/desorption analysis. The results indicate that the nickel(II)-based aerogel has very low bulk density (98kgm−3 (∼98% porous)), high surface area (413m2g−1), and has a particulate-type aerogel microstructure made up of very fine spherical particles with an open porous network. By comparison, a precipitate of Ni3(NO3)2(OH)4 is obtained when the same preparation is attempted with the common Ni(NO 3)2·6H2O salt as the precursor. The implications of the difference of reactivity of the two different precursors are discussed in the context of the mechanism of gel formation via the epoxide addition method. The synthesis of nickel(II)-based aerogel, using the epoxide addition method, is especially unique in our experience. It is our first example of the successful preparation of a metal-oxide-based aerogel using a divalent metal ion and may have implications for the application of this method to the preparation of aerogels or nanoparticles of other divalent metal oxides. To our knowledge this is the first report of a monolithic pure nickel(II)-based aerogel materials.

Synthesis and Characterization of Nickel(II) and Copper(II) Complexes with Non-symmetric Tetraaza[14]annulene Derivatives. X-ray Crystal Structure of Copper(II) Complex

The complexes 13,14-([X]benzo)-3-(p-[Y]benzoyl)-2,4,9,11-tetramethyl-1,5,8,12-tetraazacyclotetradeca-l,3,9,11-tetraenato(2-)nickel(II), wherein Y = CH3, H, Cl, NO2 or OCH3, X = CH3 or Cl, have been synthesized and characterized. IR spectra of the benzoylated complexes show intense bands in the regions 1641-1654 cm−1 attributable to the stretching modes of C—O. Hammett plots of the l/γ max of π→π ⋆ have positive slopes of 0.251 for A series (X = CH3) and 0.233 for B series (X = Cl), respectively, which are quite similar to those based on the NMR resonances of methine protons. The cyclic voltammograms of the complexes show two one-electron irreversible oxidation processes in the potential range of +0.1 to +0.8 V and two, three or four reduction peaks between −1.2 and −2.8 V depending on the substituents. Hammett plots of first and second oxidation potentials are linear with the positive slopes (0.039 and 0.057 V for A series, 0.036 and 0.047V for B series). The structure of the copper(II) complex (orthorhombic, C2221, a= 8.0994(11), b= 8.3187(10), c= 24.561(5)A, α(=β=γ)= 90.0°, Z= 4, R 1= 0.0474 and wR 2= 0.1219) was characterized using single crystal X-ray diffraction method.

Characterisation of nickel(II) extraction by 2-hydroxy-5-nonylacetophenone oxime (LIX 84) in a micellar phase

The properties of the nickel(II)/2-hydroxy-5-nonylacetophenone oxime (HNAPO), an active ingredient in LIX 84, extraction system were characterised in a micellar system. The extinction coefficient, λ max of HNAPO (316 nm) and the Ni 2+ complex (387 nm) in a neutral micellar system, poly dispersed octa-ethyleneglycol mono- n -dodecyl ether (G 12 A 8 ) were determined as 3100 and 3500 M −1 cm −1 , respectively. HNAPO was found to have a neutral micellar phase and bulk aqueous phase p K a of 11.5 and 12.5, respectively. The extraction equilibrium constant, K ex, was determined to be 10 −8.0 , and the deviation from theory observed at high pH can be accounted for by consideration of the competition for nickel(II) ions by hydroxide ions and HNAPO. A micellar phase of octa-ethyleneglycol mono- n -dodecyl ether (C 12 E 8 ) was determined to be an appropriate model of the free oil/water interface from the solubilised location of HNAPO. Utilising the interfacial probe, 4-heptadecyl-7-hydroxy coumarin (HHC) allowed the determination of the electrostatic surface potential of mixed micelles of G 12 A 8 and sodium dodecyl sulphate (SDS) or dodecyl trimethyl ammonium chloride (DTAC). The electrostatic surface potential was a linear function of the number of additional surfactant monomers within the G 12 A 8 micelle, for the concentration range studied. For G 12 A 8 /DTAC mixed micelles, the surface potential was given by +1.1 mV per DTAC molecule per micelle, and for G 12 A 8 /SDS mixed micelles the relationship was −1.4 mV per SDS molecule per micelle.

Preparation and Characterization of Nickel(Ⅱ) and Copper(Ⅱ) Tetaaza Macrocyclic Complexes with Isonicotinate Ligands

The complexes [Ni(L)(INT)2]<TEX>${\cdot}$</TEX>5H2O (1) and [Cu(L)(H2O)](Cl)(INT)<TEX>${\cdot}$</TEX>3H2O (2) (L = 3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,01.18 ,07.12 ]docosane, INT = isonicotinate) have been prepared and characterized by X-ray crystallography, electronic absorption, and cyclic voltammetry. The crystal structure of 1 reveals an axially elongated octahedral geometry with two axial isonicotinate ligands. The electronic spectra, magnetic moment, and redox potentials of 1 also show a high-spin octahedral geometry. However, 2 shows that the coordination environment around the copper atom is a distorted square-pyramid with an axial water molecule. The spectra and electrochemical behaviors of 2 are also discussed.

Synthesis and characterization of nickel(II) complexes of hexaazamacrotetracyclic ligand containing organic ligands

The complexes [Ni(H 2L)Cl 2]Cl 2·2H 2O ( 2), [Ni 2(L) 2(N 3) 4]·5H 2O ( 3) and [Ni(L)(tp)]·2H 2O ( 4) (L=1,3,10,12,15,18-hexaazatetracyclo[16,2,1,1 12.15,0 4.9]docosane; tp=terephthalate) have been synthesized and structurally characterized by X-ray crystallography, spectroscopic and cyclic voltammetry. The crystal structure of 2 has a distorted octahedral geometry with two secondary and two tertiary amines of the macrocycle and two chloride ions. In 3, the coordination geometry around the nickel atom is a distorted octahedral with four nitrogen atoms of the macrocycle and two nitrogen atoms of the azide groups. The nickel(II) ions in the complex 4 are bridged by the terephthalate anions to form infinite one-dimensional chain, which shows an elongated octahedral trans arrangement about each nickel(II) ion. The magnetic behavior of 4 exhibits a weak antiferromagnetic interaction with J value of −1.18(3) cm −1. Cyclic voltammetry of the complexes gives two one-electron waves corresponding to Ni(II)/Ni(III) and Ni(II)/Ni(I) processes. The electronic spectra and redox potentials of the complexes also reveal a high-spin six-coordinated geometry, which is reflected by the nature of the organic ligands.

ChemInform Abstract: Conjugated Macrocycles Related to the Porphyrins. Part 20. Organometallic Chemistry of Carbaporphyrinoids: Synthesis and Characterization of Nickel(II) and Palladium(II) Azuliporphyrins.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Synthesis and characterization of nickel(II) and copper(II) complexes with a tetramethyltetraaza macrocycle containing 2-pyridylmethyl pendant arms

The complexes [Ni(L 2)](ClO 4) 2·H 2O ( 1) and [Cu(L 2)]Cl 2·4H 2O ( 2) have been synthesized and characterized by X-ray crystallography, electronic absorption and cyclic voltammetry. The crystal structure of 1 reveals a distorted octahedral geometry with four nitrogen atoms of the macrocycle and two nitrogen atoms of the pendant pyridylmethyl groups. The structure of 2 shows that the complex is centrosymmetric and the metal center has a tetragonally distorted octahedral environment. The electronic spectra and electrochemical behaviors of the complexes are significantly affected by the presence of the pendant arms.

Organometallic chemistry of carbaporphyrinoids: synthesis and characterization of nickel(II) and palladium(II) azuliporphyrins.

Brief treatment of azuliporphyrins 5 with nickel(II) or palladium(II) acetate in refluxing DMF afforded excellent yields of the related chelates; these novel organometallic compounds retain cross-conjugated borderline aromatic structures as judged by UV-Vis and NMR spectroscopy, and X-ray crystallography.

Synthesis and Characterization of Nickel, Cobalt and Iron Raney Catalysts Prepared by Mechanical Alloying and Alkaline Leaching

Synthesis and Characterization of Nickel, Cobalt and Iron Raney Catalysts Prepared by Mechanical Alloying and Alkaline Leaching

The synthesis and characterization of nickel(II) and copper(II) complexes with the polydentate dialkyl dithiocarbamic acid ligand 3-dithiocarboxy-3-aza-5-aminopentanoate

Square planar complexes of Ni(II) and Cu(II) with potassium 3-dithiocarboxy 3-aza-5-aminopentanoate have been prepared by direct synthesis. The obtained neutral complexes were characterized by elemental analysis, magnetic susceptibility measurements, infrared and electronic spectra. The thermal behaviour of both the Ni(II) and Cu(II) complexes, and the ligand itself was investigated by DSC and TG.

Synthesis and Characterization of Nickel, Cobalt and Iron Raney Catalysts Prepared by Mechanical Alloying and Alkaline Leaching

Synthesis and Characterization of Nickel, Cobalt and Iron Raney Catalysts Prepared by Mechanical Alloying and Alkaline Leaching