This work described that a glassy carbon electrode was modified by Schiff base nickel complexes-graphene oxide (Ni-GO) and used for determination of L-cysteine. It concluded that electronic media effect of the nickel complexes and larger specific surface area of the graphene oxide result from L-cysteine had a good cyclic voltammetry behavior on the modified electrodes. The modified electrode was suitable to assay the content of L-cysteine, a new method for measuring the content of L-cysteine was established, which was simple manufacture, convenient operation, safety and environmental protection.
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The octahedral Ni(II) Complexes should have magnetic moments ranging from 2.9 to 3.9 B.M. depending upon the magnitude of orbital contribution and tetrahedral nickel complexes have moment ranging from 3.5 to 4.2 B.M. In the present complexes magnetic moment lie in between 3.36- 3.30 B.M. which is well in the range for octahedral complex 5-6 .
In our laboratory, several derivatives of hydroxyl- naphthalenediones and their metal complexes have been studied, particularly with their antimicrobial and antifungal activity. The complexes with sulpher, nitrogen and oxygen impart special biological activity [1-4], particularly thiosemicarbazone derivatives [5-9]. The inhibitory action of these compounds is given to their chelating properties [10-16]. In the present work the antimicrobial study of thiosemicarbazone derivative of Lawsone  and its complexes with Ni(II), where the change of ligating system from O O , O N to O N S. is studied.
Transition metal complexes and two new Schiff bases were prepared. These compounds were evaluated by various spectroscopic techniques. The physical and spectral data revealed monobasic tridentate nature of Schiff base and ligand to metal ratio of 2:1 for cobalt complex and 1:1 for copper, zinc and nickel chelates. Octahedral arrangement for cobalt complexes, square planar geometry for nickel complexes, the distorted square planar configuration for copper complexes and tetrahedral geometry for zinc complexes have been predicted. The biological activity studies revealed the higher antibacterial and antitubercular activity of metal chelates compared to parent ligand against ESBL and MBL uropathogens and M. Tuberculosis.
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The thermodynamic and kinetic decomposition of bis(N-alkyl-2-hydroxonapthaldimine)nickel(II) (N-alkyl = me- thyl, ethyl, propyl, butyl or pentyl) complexes were carried out. The molecular masses of the homologous series of the nickel complexes were obtained from FABMS. The TG-based transpiration technique was used to eva- luate the vapor pressure data of bis(N-alkyl-2-hydroxonapthaldimine)nickel(II) homologues. The standard en- thalpies of vaporization and entropies of vaporization of the complexes have been evaluated. The non-isothermal vaporization activation energy values were determined by Arrhenius and Coats-Redfern methods.
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(Chichang et al., 1987), in Table 1, along with those of two nickel complexes of related dialkyl phosphorodithioate ligands, (III) and (IV) (Gray et al., 2003, 2004), and a similar zinc complex, (V) (Ivanov et al., 2000). The title mononuclear nickel complex is shown in Fig. 1, where the Ni atom resides on a crystallographic inversion center and is coordinated by four S atoms in a distorted square-planar geometry with symmetric NiS 2 P rings and Ni—S distances of 2.2192 (5) and
In the green nickel complexes of type I, [Ni(L) 2 ], the ligands are present in ketonic form while in orange type II, [Ni(L)] 2 they are bonded in enolic for m as revealed by the I.R. spectra of the complexes. The tendency of such ligands to act in enolic form largely depends upon the aromaticity of
Nickel catalyst are of great interest due to the fact that it’s cheap. Different nickel (II) complexes has been synthesised over the past few decades which had high efficiency and selectivity. Nickel complexes has been identified as most the effective catalyst in oxidation of alcohols into carbonyl compounds, which is one of the most pivotal functional group transformations in organic synthesis . A series of nickel (II)-triphenylphosphine complexes with derivatives of N-(2-pyridyl)-N’-(salicylidene) hydrazine has been synthesised (NiL1-NiL5) and their application in oxidation of alcohols to carbonyl compounds in ethyl-methyl imidazolium (EMIM) ionic liquid has been investigated. To study the catalytic activity a solution of nickel complex ( 0.02 mmol) in 0.1 mL EMIM was added to the solution of benzyl alcohol (1 mmol) and NaOCl ( 1 mmol) and periodically reaction mixture was removed and analysed using Gas chromatography. It has been observed that total reaction time was only 15 min even at room temperature. This proves that Ni (II) complex/EMIM-NaOCl system showed great efficiency. It has also been observed that catalytic activity reduces dramatically with increase in the size of substituents. To find out the effect of concentration of catalyst with respect to substrate, the reaction was carried out in different substrate to catalyst ratio and it has been found that 0.02 mmol of catalyst was sufficient for maximum conversion of benzyl alcohol to corresponding carbonyl group. This observations shows the catalytic activity of Nickel (II) complexes. Same reaction was studied under different substrates and all the alcohols were oxidized from good to excellent conversions without adding any additives. All nickel complexes were found to catalyse the oxidation of alcohols to corresponding carbonyl compounds in a conversion range of 60-96%. Experimental data’s are given in table 3 below 
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shifted to lower energies. These results showed that the Cu (II) and Ni (II) ions are coordinated through the nitrogen atoms of the amine group, oxygen atom of the phenolic group and sulfur of the C=S group for two complexes. Figs. 1 and 2 show the comparison of XRD patterns, simulated from single crystal X-ray data against the nano powder of compounds 1-2 prepared by the hydrothermal method, respectively. The comparison between
Nickel is widely used in electroplating, the manufacture of Ni-Cd batteries, rods for arc welding, pigments of paints, ceramic, surgical and dental prostheses, magnetic tapes and computer components and nickel catalysts. Nickel enters waters from dissolution of industrial processes and waste disposal. Nickel is essential constituent in plant urease. Jack beans and soybeans generally contain high concentration of nickel. 
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The ionization constants of various ligands were calculated using the computer program PKAS . Entire pH range from the titration data has been given for the calculation of pKa values using the computer program. All the formation or stability constants were subjected to refinement using the computer program BEST . The refinement of the stability constants of binary and ternary systems were done by considering all possible species present in the solution, i.e., HL + , HA, L-, A-, ML, ML2, MA, MA2 and MAL etc, where L and A are different ligands in the complex. The refined values for these complexes thus obtained are provided in the Tables. The error limits in these constants were minimized (sigma fit is 0.001).
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100 ml of ethanol, to which nickel(II) acetate (0.33 g, 1.3 mmol) was added. A red precipitate began to form after approximately 30 min. The solution was then allowed to stir for 1 h, followed by cooling in a freezer and filtration of the crude product (yield: 272 mg, 0.2 mmol, 32%). The resulting product was dissolved in DMF solution and layered with toluene, resulting in the formation of crystals of [Ni 3 (H 2 pqd)(Hpqd) 2 (pqd) 2 ] after a period of 3–4 d. The
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Nickel complex (335 mg,); and copper complex (500 mg) were taken separately and disperse in 10 ml of ethylene glycol in separate beaker. Then the solutions were injected separately into three-neck round bottom flask (250 ml) containing preheated (at 120⁰C) 60 ml ethylene glycol, with vigorous stirring. Stirring with heating were continued 2 hours. During stirring, black precipitates were observed for both the experiments. After that the solution was cooled to room temperature and the precipitates were separated through centrifuge. The products were washed with water and ethanol for a number of times for purification. Finally, the products were dried and used for spectral analysis.
Glimeperide was reacted with different metal salts of essential and trace metals in 1:2 metal ligand ratio forming coloured crystaline complexes. The physico-chemical and analytical data of complexes of given on table (3). The complexes formed with Copper, Magnesium, Nickel and Cadmium are diamagnetic and non-ionic in nitrobenzene.
Thermogravimetric studies of the sodium salt of poly(acrylic acid), its modified sodium salt and its various metal complexes were made. The metal-ion complexation of carboxylate ligands of linear poly(acrylic acid), optimization of the complexation conditions and infra-red and ultraviolet-visible spectrometric characterizations are also illustrated 6 .
Metal complexes of dithiocarbamate are well known for their biochemical importance. The clinical application and toxicological and inhibitory action of dithiocarbamate is also well known. In view of the wide range of applications of dithiocarbamates and various aspects of bioactivity of Schiff base our attempt to synthesize and characterize Cu(II) mixed ligand complexes of the type [Cu(pyrrdtc)SB] where SB= Schiff base was successful. The assignment of four coordinate geometry was corroborated by analytical data and infra-red spectral data. The antibacterial activity of the mixed ligand complexes were tested against Streptococcus pneumoniae, Klebsiella subtilis, Escherichia Coli and Staphylococcus aureusand they showed considerable activity against the test bacteria.
established by their microanalysis, while the metal contents have been determined gravimetrically and volumetrically. On the basis of IR spectra, the coordinating mode of ligand has been determined and has been found to have coordinated through azomethine nitrogen and thione sulphur. The magnetic moment of Co(II) complexes has been found between 4.96-4.72 B. M. The value is slightly higher than the µ s value corresponding to three unpaired electrons (3.872 B.M). The increase in value may be attributed to orbital contribution from 4 T
Benzaldehyde (0.283 mL, 2.775 mmol) was added dropwisely into 2,2′–bipypridine (0.4334 g, 2.775 mmol) dissolved in 5 mL methanol while stirring; copper (II) nitrate trihydrate (0.6704 g, 2.775mmol) was then added into the solution. The resulting mixture was stirred for an hour and the complex formed was filtered, washed with methanol and dried. Similar procedure was used for the preparation of the phenanthroline and ethylenediamine complexes. Preparation of [Ni(Bz) 2 BipyCl 2 ] (1:1:1)
All the chemicals and solvents employed were of BDH and Sigma Aldrich quality and used without further purification. The chemicals include methyl-4-nitrobenzoate, meta-hydroxybenzaldehyde, hydrazine hydrate, copper(II) chloride dihydrate, nickel(II) chloride hexahydrate. Ethanol and Methanol. The metal contents (w/w %) were determined by complexometric titration of EDTA using murexide indicator and ammonia/ammonium chloride buffer. IR spectra were recorded as nujol in the range 450-4000 cm -1 on a Perkin Elmer FT-IR Spectrophotometer. UV-Vis spectra of the samples as solid diffuse reflectance were measured in the range 200-1000 cm -1 using a Shimadzu UV-Vis 1800 Spectrophotometer. 1 H (300 MHz) NMR Spectra were recorded on a Bruker DMX avance spectrophotometer (with
A single-pass method for the ion-exchange separations of binary mixtures of metals is described, and experimental applications are presented. The method consists of complexing each of the components in the mixture with a separate complexing agent at a pH sufficient to ensure maximum coordination of the metals. The complexing agents are chosen such that the metal complexes formed are of opposite charge. The mixture is then passed through an ion-exchange resin which absorbs one species completely, allowing the other to be collected in the effluent. An anion-or cation-exchange resin is used.
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