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A novel durable and reliable eco-friendly activated charcoal (AC) plastic membrane sensor was established for the determination of nickel in real and spiked samples. Different amounts (1-8 mg) of AC were tested for the sensor preparation. The membrane containing 2 mg of activated charcoal showed the best performance. The Ni.sup.2+-sensor showed a Nernstian slope of 29.8 mV/decade over a wide concentration range of 5 x 10.sup.-6-5 x 10.sup.-2 M with the correlation coefficient for the determination of 0.9971 and detection limit of 2.0 x 10.sup.-6 M. The fabricated sensor showed fast response time (5 s) and was used for a long period of more than 4 months. The sensor exhibited a wide working pH range of 3.7-7.4. The sensor was applied for the determination of nickel in banana and organic solvents like methanol, ethanol and N,N-dimethylformamide with the average recovery of 100.0% and average RSD of 1.9%., Author(s): Mohsen M. Zareh [sup.1] , Nora O. Saleem [sup.1] , AbdAlnasser Abd-ElSattar [sup.1] Author Affiliations: (1) grid.31451.32, 0000 0001 2158 2757, Department of Chemistry, Faculty of Science, Zagazig University, [...]

The reaction of 1,3,5-[([.sup.i][Pr.sub.2]]PO).sub.3][C.sub.6]H3 with [Co.sub.2][(CO).sub.8] leads to the isolation of a POCOP-type mononuclear pincer complex {[K.sup.P],[K.sup.C],[K.sup.P]-2,4,6-[([.sup.i][Pr.sub.2]]PO).sub.3]C6[H.sub.2]}Co[(CO).sub.2] [(1) or a tetranuclear species {[K.sup.P]-{[K.sup.P],[K.sup.C],[K.sup.P]-2,4,6-[([.sup.i][Pr.sub.2]]PO).sub.3][C.sub.6][H.sub.2]}Co[(CO).sub.2]}.sub.2][Co.sub.2][(CO).sub.6] (2), depending on the ligand to cobalt ratio employed. The latter compound can be an impurity during the synthesis of {2,6-[([.sup.i][Pr.sub.2]]PO).sub.2]-4-[Me.sub.2]N-[C.sub.6][H.sub.2]}Co[(CO).sub.2], when the ligand precursor 5-(dimethylamino)resorcinol is contaminated with phloroglucinol due to incomplete monoamination. Similarly, the reaction of 1,3,5-[( [.sup.i][Pr.sub.2]]PO).sub.3]C6H3 with [NiCl.sub.2] in the presence of 4-dimethylaminopyridine provides {[K.sup.P],[K.sup.C],[K.sup.P]-2,4,6-[([.sup.i][Pr.sub.2]]PO).sub.3][C.sub.6][H.sub.2]}NiCl (3) bearing an appended phosphinite group. Structures 1-3 have been studied by X-ray crystallography. Key words: phosphinite, pincer complexes, C-H activation, appended functionality, catalyst immobilization. La reaction du 1,3,5-[([.sup.i][Pr.sub.2]PO).sub.3][C.sub.6][H.sub.3] avec le [Co.sub.2][(CO).sub.8] permet d'isoler le complexe de ligand pince mononucleaire de type POCOP{[K.sup.P],[K.sup.C],[K.sup.P]-2,4,6-[([.sup.i][Pr.sub.2]PO)3[C.sub.6][H.sub.2]}Co(CO).sub.2] [(1)oul'especetetranucleaire[{[K.sup.P]-{[K.sup.P],[K.sup.C],[K.sup.P]-2,4,6-([.sup.i][Pr.sub.2]PO)3[C.sub.6][H.sub.2]}Co(CO).sub.2]}.sub.2][Co.sub.2][(CO).sub.6](2), selon le rapport ligand-cobalt utilise. Cette derniere espece peut etre une impurete issue de la synthese du {2,6-[([.sup.i][Pr.sub.2]]PO).sub.2]-4-[Me.sub.2]N-[C.sub.6][H.sub.2]}Co[(CO).sub.2], lorsque le precurseur de ligand 5-(dimethylamino)resorcinol est contamine par du phloroglucinol en raison d'une monoamination incomplete. De maniere similaire, la reaction du 1,3,5-[([.sup.i][Pr.sub.2]PO).sub.3][C.sub.6][H.sub.3] avec le [NiCl.sub.2] en presence de 4-dimethylaminopyridine produit le {[K.sup.P],[K.sup.C],[K.sup.P]-2,4,6-([.sup.i][Pr.sub.2]PO)3[C.sub.6][H.sub.2]}NiCl (3) portant un groupe phosphinite attache. Nous avons etudie les structures 1-3 par radiocristallographie. [Traduit par la Redaction] Mots-cles : phosphinite, complexes de ligands pinces, activation de liaison C-H, groupe fonctionnel attache, immobilisation du catalyseur., Introduction Diphosphinite-derived POCOP-type pincer complexes have been studied extensively as homogeneous catalysts for a wide variety of organic transformations (.1-11) To facilitate catalyst-product separation and catalyst recycling, (12), (13) Lewis [...]

Amides are common functional groups that have been studied for more than a century (1). They are the key building blocks of proteins and are present in a broad range of other natural and synthetic compounds. Amides are known to be poor electrophiles, which is typically attributed to the resonance stability of the amide bond (1,2). Although amides can readily be cleaved by enzymes such as proteases (3), it is difficult to selectively break the carbon-nitrogen bond of an amide using synthetic chemistry. Here we demonstrate that amide carbon-nitrogen bonds can be activated and cleaved using nickel catalysts. We use this methodology to convert amides to esters, which is a challenging and underdeveloped transformation. The reaction methodology proceeds under exceptionally mild reaction conditions, and avoids the use of a large excess of an alcohol nucleophile. Density functional theory calculations provide insight into the thermodynamics and catalytic cycle of the amide-to-ester transformation. Our results provide a way to harness amide functional groups as synthetic building blocks and are expected to lead to the further use of amides in the construction of carbon-hetero-atom or carbon-carbon bonds using non-precious-metal catalysis., The ability to interconvert functional groups is important in synthetic chemistry and many biological processes. Methodologies (4,5) have been developed that enable chemists to strategically harness the reactivity of most [...]

Kinetic sorption and column miscible displacement transport experiments were performed to quantify the extent of retention and the mobility of Ni in different soils. Results from kinetic sorption indicated that sorption of Ni was time dependent and highly nonlinear, with the sorption affinity of Webster loam (a fine-loamy, mixed, superactive, mesic Typic Endoaquoil) > Olivier loam (a fine-silty, mixed, active, thermic Aquic Fraglossudalf) > Windsor sand (a mixed, mesic Typic Udipsamment). A multireaction and transport model (MRTM) was capable of describing the observed nonlinearity and time-dependent adsorption of Ni for all the soils. Column transport experiments showed that Ni mobility was strongly retarded, with extensive tailing or slow release during leaching. In the Webster soil, breakthrough results revealed that Ni was highly immobile, where doi: 10.2136/sssaj2010.0006

A procedure based on microwave-induced combustion (MIC) was applied for carbon nanotabe (CNT) digestion and further determination of La and Ni by inductively coupled plasma optical emission spectrometry (ICP OES). Samples (up to 400 mg) were completely combusted at 20 bar of oxygen, and a reflux step was applied to improve the analyte absorption. Combustion was finished in less than 50 s, and analytes were absorbed in diluted acid solution. Absorbing solutions ranging from 1 to 12 mol [L.sup.-1] for HCl and from 1 to 14 mol [L.sup.-1] HN[O.sub.3] were tested. Accuracy for both analytes was evaluated using certified reference materials and analyte spikes. Neutron activation analysis was also used to check accuracy for La. Agreement was better than 96% for La and Ni using a 4 mol [L.sup.-1] absorbing solution of HN[O.sub.3] or HCl and 15 min of reflux. The residual carbon content was lower than 0.5%. Up to eight samples could be digested simultaneously in 36 min, that makes the throughput using MIC more suitable when it is compared to the digestion by dry ashing as recommended by other procedures. The obtained limits of detection using MIC were lower than those using dry ashing, and a single absorbing solution, e.g., diluted HN[O.sub.3], can be used for simultaneous determination of La and Ni by 1CP OES. 10.1021/ac100429v

A computational approach has been undertaken to design and assess potential Fe--Cr--Ni--Al systems to produce stable nanostructured corrosion-resistant coatings that form a protective, continuous scale of alumina or chromia at elevated temperatures. The phase diagram computation was modeled using the THERMO-CALC[R] software and database (Thermo-Calc[R] Software, 2007, THERMO-CALC for Windows Version 4, Thermo-Calc Software AB, Stockhohn, Sweden; Thermo-Calc[R] Software, 2007, TCFE5, Version 5, ThermoCalc Software AB, Stockholm, Sweden) to generate pseudoternary, Fe--Cr--Ni--Al phase diagrams to help identity compositional ranges without the undesirable brittle phases. The computational modeling of the grain growth process, sintering of voids and interface toughness determination by indentation, assessed microstructural stability, and durability of the nanocoatings fabricated by a magnetron-sputtering process. Interdiffusion of Al, Cr, and Ni was performed using the DICTRA[R] diffusion code (Thermo-Calc Software[R], DICTRA, Version 24, 2007, Version 25, 2008, Thermo-Calc Software AB, Stockholm, Sweden) to maximize the long-term stability of the nanocoatings. The computational results identified a new series of Fe--Cr--Ni--Al coatings that maintain long-term stability and a fine-grained microstructure at elevated temperatures. The formation of brittle [sigma]-phase in Fe--Cr--Ni--Al alloys is suppressed for Al contents in excess of 4 wt %. The grain growth modeling indicated that the columnar-grained structure with a high percentage of low-angle grain boundaries is resistant to grain growth. Sintering modeling indicated that the initial relative density of as-processed magnetron-sputtered coatings could achieve full density after a short thermal exposure or heat-treatment. The interface toughness computation indicated that the Fe--Cr--Ni--Al nanocoatings exhibit high interface toughness in the range of 52-366 J/[m.sup.2]. The interdiffusion modeling using the DICTRA software package indicated that inward diffusion could result in substantial to moderate Al and Cr losses front the nanocoating to the substrate during long-term thermal exposures. [DOI: 10.1115/1.3204651]

We report here a highly selective enzymeless approach for the determination of phosphate ([PO.sub.4.sup.3-]) by flow injection analysis (FIA). In this system, the activation of barrel plated nickel electrode (Ni-BPE) in alkaline media to form a [Ni(OH).sub.2]/NiO(OH) film was found to trigger the adsorption of phosphate at the electrode surface. Based on the suppressed current of the electrocatalytic oxidation of glucose at the activated Ni-BPE in 0.1 M NaOH solution caused by adsorption of phosphate, we develop an FIA detection scheme for the determination of phosphate. Under the optimized conditions of flow rate =300/[mu]L/min and detection potential =0.55 V vs Ag/AgCI with 25/[mu]M glucose in 0.1 M NaOH as carrier solution, the calibration curve showed a linear range up to 1 mM. Possible interferences from the coexisting ions were also investigated. The results demonstrated that sensor could be used for the determination of phosphate in the presence of nitrate, chloride, sulfate, acetate, oxalate, carbonate, and some anionic species of toxicological and environmental interest, such as chlorate, chromate, and arsenate ions. The electrode can be effectively regenerated without extra treatment under the hydrodynamic condition. For eight continuous injections of 40 [mu]M [PO.sub.4.sup.3-] , a relative standard deviation of 0.28% was obtained, indicating good reproducibility of the proposed method. The detection limit (S/N = 3) was calculated as 0.3 [mu]M. 10.1021/ac9025253

Hydrogen production through the reduction of water appears to be a convenient solution for the long-run storage of renewable energies. However, economically viable hydrogen production requests platinum-free catalysts, because this expensive and scarce (only 37 ppb in the Earth's crust) metal is not a sustainable resource [Gordon RB, Bertram M, Graedel TE (2006) Proc Natl Acad Sci USA 103:1209-1214]. Here, we report on a new family of cobalt and nickel diimine-dioxime complexes as efficient and stable electrocatalysts for hydrogen evolution from acidic nonaqueous solutions with slightly lower overvoltages and much larger stabilities towards hydrolysis as compared to previously reported cobaloxime catalysts. A mechanistic study allowed us to determine that hydrogen evolution likely proceeds through a bimetallic homolytic pathway. The presence of a proton-exchanging site in the ligand, furthermore, provides an exquisite mechanism for tuning the electrocatalytic potential for hydrogen evolution of these compounds in response to variations of the acidity of the solution, a feature only reported for native hydrogenase enzymes so far. bio-inspired chemistry | cobaloxime | electrocatalysis | hydrogen evolution reaction | hydrogenase doi/10.1073/pnas.0907775106

Cobalt and nickel in olivine from lunar, martian, and terrestrial basalts show systematic differences that appear to be related to planetary parentage. We present results from a series of 1 atm experiments designed to examine the partitioning of Co and Ni in olivine over a range of conditions relevant to planetary basalts. Our results confirm the suggestions of previous workers that the partitioning of Co is such that an increase in [D.sup.ol.sub.Co] with crystallization is balanced by a decrease in Co concentration in the melt, resulting in constant Co in olivine, either within olivine showing otherwise normal igneous zoning, or within a suite of basalts related by fractionation. It is evident that the partitioning of Co and Ni into planetary olivine is influenced by such intensive variables as temperature, oxygen fugacity, and composition. Although separating these effects is not possible, our data demonstrate that over the range of oxygen fugacity of lunar, martian, and terrestrial basalts, oxygen fugacity has no significant effect on Co and Ni partitioning into olivine. We propose that an increase in melt polymerization with decreasing temperature, coupled with the preference of Co and Ni for the octahedral sites in olivine, is the mechanism by which [D.sup.ol.sub.Co] and [D.sup.ol.sub.Ni] increase with crystallization. With our experimental results as a baseline, we interpret data from Co and Ni in olivine from lunar, martian, and terrestrial basalts and conclude that the cause of increases in Co concentrations in olivine, either core-to-rim or within a co-genetic suite and observed primarily in martian and terrestrial basalts, is enrichment of the melt as crystallization progresses. We hypothesize that this enrichment is attributable either to crystallization of a phase in which Co is incompatible (such as plagioclase) or replenishment of the igneous system with Co-enriched melt. Keywords: Nickel, cobalt, olivine, basalt, terrestrial, Earth, martian, Mars, lunar, Moon, oxygen fugacity, experimental petrology

Biomass gasification by the use of metallic nickel as active metal on dolomite support has been chosen as catalyst because of its activity in biomass steam gasification and tar reduction. The purpose of this study is to study the effects of critical parameters on product gas compositions such as temperature, steam to carbon ratio (S/C) and oxygen input. The results showed the increasing carbon conversion to gas from 44.13-78.43% whereas tar was decreased from 19.55-1.4% at temperature of 800[degrees]C and S/C 0.95. It is found that Nickel-dolomite is effective for tar reduction and for improving the quality of syngas derived from biomass which is a renewable energy source. Key words: Tar, biomass, gasification, Ni/dolomite, coconut shell, INTRODUCTION Gasification of biomass is a potential source of renewable energy to produce useful gases such as syn gas or pure hydrogen. One of the major issues in biomass gasification [...]

The synthesis and characterization of salen (N, N'-(disalicylidene)ethylenediamine, deprotonated form) complexes of group 10 metal ions, Ni(II), Pd(II) and Pt(II), are described. The results have shown the versatile nature of the group 10 metal ions in the 2N2O-donor tbu-salen coordination sphere.

Five novel arylsulfonates of Ni and Co are obtained hydrothermally and their structures are determined by X-ray single-crystal diffraction. Self-assembly interactions of all the five compounds have shown that one of them is a polymeric hydrogen-bonded supramolecular layered compound formed by self-assembly of tetraaquo-o-phenanthrolinenickel(II) cations and 1,5-NDS (naphthalenedisulfonate) anions, two are also 2D structures through O-H...O and [pi]-[pi] stacking interactions and only one presents a 3D structure through O-H...O hydrogen-bond layers and [pi]-[pi] parallel-displaced stacking interactions.

The effect of anharmonicity on the adsorption of CO molecules on the Ni(111) surface is investigated. Isochoric heat capacity and entropy depend on the model potential significantly, and the differences might be as high as 69% and 55% for isochoric heat capacity and entropy, respectively.

Fourier transform infrared spectroscopy is used to study the different redox intermediates of [NiFe] hydrogenase of Desulfovibrio vulgaris Miyazaki F. It is shown that the Fe carries one carbon monoxide molecule and two [CN.sup.-] molecules as ligands as found for D. gigas and A. vinosum hydrogenase, indicating high degree of similarity among these three enzymes.

The B[H.sub.3]-protected phosphinoindenyl ligand indenyl[(C[H.sub.2]).sub.2]P[Ph.sub.2]xB[H.sub.3] was used in the preparation of [([[eta].sup.5/3]:[[eta].sup.0]- indenyl[(C[H.sub.2]).sub.2]P[Ph.sub.2]xB[H.sub.3]) Ni(P[Ph.sub.3])Cl, which has been characterized by NMR spectroscopy and X-ray diffraction studies. On the other hand, all attempts at preparing the closely related complex [[eta].sup.5/3]: [[eta].sup.1]-indenyl(C[H.sub.2]).sub.2]P[Ph.sub.2])NiCl, in which the tethered phosphine moiety is coordinated to the Ni centre, were unsuccessful. One of these unsuccessful attempts yielded instead the novel indenyl-PCP pincer complex {[[kappa].sup.P],[[kappa].sup.C], [[kappa].sup.P]-1/3-[(C[H.sub.2]) C[H.sub.2]P[Ph.sub.2]).sub.2]-2-indenyl}NiCl, which has been characterized by X-ray diffraction studies. Key words: indenyl complexes, tethered phosphines, PCP pincer complexes. Le ligand protege indenyl [(C[H.sub.2]).sub.2]P[Ph.sub.2]xB[H.sub.3] a permis la preparation du compose ([eta].sup.5/3]:[[eta].sup.0] -indenyl [(C[H.sub.2]).sub.2]P[Ph.sub.2]xB[H.sub.3])Ni(P[Ph.sub.3])Cl. Ce dernier a ete completement caracterise par la spectroscopie RMN et etudes cristallographiques. Toutes les tentatives de preparer et isoler le complexe ([[eta].sup.5/3]:[[eta].sup.1]-indenyl(C[H.sub.2]).sub.2]P[Ph.sub.2])NiCl ont echoue. En revanche, nous avons obtenu lors d'une de ces tentatives un nouveau complexe inattendu; une etude cristallographique a demontre que ce dernier etait un complexe de type [??] pincer [??] PCP-indenyle, soit {[[kappa].sup.P], [[kappa].sup.C], [[kappa].sub.P] -1,3-(C[H.sub.2]C[H.sub.2]P[Ph.sub.2]).sub.2] -2-indenyl}NiCl. Mots cles : complexes d'indenyle, phosphines attachees, complexe de type [??] pincer [??] PCP.

Silole-core dendrimers having benzyl-ether-type dendron units in the periphery are readily synthesized by the Ni-catalyzed reaction of benzyloxy-substituted diphenylacetylenes with 1,1,2,2-tetramethyldisilane. Key words: silole, dendrimer, nickel-catalyzed reaction, convergent synthesis. La synthese de dendrimeres a coeur de silole possedant des dendrones de type ether benzylique a la peripherie peut etre realisee facilement en faisant appel a la reaction du 1,1,2,2-tetramethyldisilane avec des diphenylacetylenes substitues par un groupe benzyloxy, catalysee par du nickel. Mots cles : silole, dendrimere, reaction catalysee par le nickel, synthese convergente. [Traduit par la Redaction]

Nickel formate serves as an ideal catalyst precursor for surface-bound thermal and plasma-enhanced CVD growth of carbon nanotubes. As the method of deposition of the Ni catalyst is solution-based, it benefits from a low-cost, large-area growth, ease of operation and suitability for coating substrates with complex shapes and structures.

Discrete nickel catalyst nanoparticles have been used to grow isolated single-walled carbon nanotubes by chemical vapor deposition. Atomic force microscopy, transmission electron microscopy, and micro-Raman spectroscopy have been used to characterize the as-grown, isolated nanotubes.

Solid-state coordination chemistry of the oxomolybdate-organodiphosphonate/nickel-organoimine system is presented. A polyhedral representation of the structure of [{Ni3 (tpyprz)(sub 2)(H2O)(sub 2)}-(Mo5O15)(Mo2F2O4){O3P(CH2)(sub 3)PO3}(sub 2)] is shown.

The mechanism of NiFe site biosynthesis in Ralstonia eutropha is investigated by examining the interactions between HypC, HypD, HypE, and HypF1. In respect to Hyp proteins, it is shown that HypE and HypF1 formed a stable complex both in vivo and in vitro.

A detailed structural data is obtained for LixMg(sub 0.1)Ni(sub 0.4)Mn(sub 1.5)O(sub 4) spinels, intercalated with lithium in the range 1less than equal to x less than equal 2.25, by simultaneous reitveld refinement of X-ray and neutron diffraction data. Extensive migration of Ni and Mn duringlithium insertion is found, resulting in the disappearance of the initial Ni-Mn ordering and the formation of Ni-rich and Ni-poor domains.

A series of mono- and dinuclear Ni(II), Co(II), and Cu-(II) complexes of chiral ligands derived from 1,1'-binaphthyl-2,2'-diamine (BINAM) were synthesized and characterized. Complex formation was found to be highly diastereoselective and ligand self sorting based on chirality.

Addition of BF3.OEt2 to ethereal solutions of the Ni(II) beta-diketiminates allows the isolation of the neutral beta-H agostic monoalkyls[Me2NN]Ni(R). X-ray studies of the primary alkyls [Me2NN]Ni(R) reveal acute Ni-C(sub alpha)-C(sub beta) distances, indicating structures along the beta-H elimination pathway.

An investigation on the adsorption of formate and acetate on the Ni(110) surface is presented with STM, LEED, TPRS, and XPS. The study concluded that the added Ni in the formate structure facilities the decomposition of formate into CO2, H2, and scattered Ni(sub x) nuclei, which act as sites for further formate decomposition.

The molecular structures of [Ni (H-4)](sub 2) and [Zn (H-4)](sub 4) are determined by X-ray diffraction. The findings indicate distorted tertrahedral coordination geometry for the zinc (II) ions in an NS(sub 3) coordination sphere.

Sulfur bridging interaction between three cis-planar Ni(super II)-S2N2 complex and Ni(super II), Cu(super I, II), Zn(super II), and Hg(super II) reactants are investigated by synthesis and X-ray crystal structures of some 24 complexes. This work is stimulated by recent crystallographic structures of the A-cluster of carbon monoxide dehyrogenase/acetylcoenzeme a synthase.

Addition of arylithium followed by ring closure with boron trifluoride produced a blue-emitting ladder-type pentaphenylene. Bromination followed by reductive polymerization with nickel (0) gave new high molecular mass polymers, which show efficient blue emission with a very small Stokes shift.

The phase transformation and sheet resistance of Nickel on single crystalline SiGe(C) layers after annealing treatments at 360-900 degree Celsius is investigated. A large interfacial roughness was obtained in the Ni(SiGe) layers, whereas the Ni(SiGeC) layers demonstrated a smoother surface.

A method using nickel enolates developing a new strategy for effecting cascade cyclization processes is described. It is observed that the rapid synthesis of complex polycyclics from simple achiral, acyclic precursors is permitted by the partially or fully intramolecular versions of the process.

Abstraction of [Cl.sup.-] from the complexes (indenyl)Ni(P[Ph.sub.3])Cl generates cationic species that are effective precatalysts for the hydrosilylation of some olefins and ketones. For instance, the mixture of (1-Me-indenyl)Ni(P[Ph.sub.3])Cl and NaB[Ph.sub.4] (or methylaluminoxane) reacts at room temperature with ca. 100 equiv. each of PhSi[H.sub.3] and styrene to produce [1-phenyl-1-ethyl](phenyl) silane, PhCH(C[H.sub.3])(SiPh[H.sub.2]), in 50%-80% yield. The same system can also catalyze the hydrosilylation of 1-hexene and norbornene, but the products arising from these substrates consist of mixtures of regio- and stereoisomers. On the other hand, ketone hydrosilylation is regiospecific, giving the corresponding silyl ethers in high yields. A number of experimental observations have indicated that the initially generated Ni-based cation is not the catalytically active species. Indeed, the cationic initiators may be replaced by LiAl [H.sub.4] or Al[Me.sub.3], which generate the corresponding Ni-H or Ni-Me derivatives, respectively. Moreover, the observed regioselectivity for the addition of PhSi[H.sub.3] to styrene (i.e., predominant addition of the silyl fragment to the [alpha]-C) is opposite of what would be expected if the reaction mechanism involved carbocationic intermediates. A new mechanism is proposed in which the active species is a Ni-H species originating from the transfer of [H.sup.-] from PhSi[H.sup.3] to the initially generated Ni cation. Key words: hydrosilylation, nickel indenyl complexes, cationic complexes, hydride intermediates.

Thiocyanatonickel(II) compounds with composition {[(As[Ph.sub.4]).sub.2][Ni[(NCS).sub.4]]} 1, {(Cat)[Ni[(NCS).sub.4]]} 2, {(As[Ph.sub.4]).sub.4][[Ni.sub.2][(NCS).sub.8]] } 3, {[(Cat).sub.2] [[Ni.sub.2][(NCS).sub.8]]*2[CH.sub.3][NO.sub.2]} 4, and {[([Et.sub.4]N).sub.4][Ni[(NCS).sub.6]]} 5 ([Cat.sup.2+] = [(p-xylylenebis(triphenyphosphonium)).sup.2+]) were prepared. The crystal structures of compounds 1, 3, and 4 were determined. Compound 1 crystallizes in the monoclinic C2/c space group with a = 22.761(2) [Angstrom], b = 15.055(1) [Angstrom], c = 15.054(1) [Angstrom], [beta] = 108.915(1)[degrees], V = 4879.9(6) [Angstrom].sup.3], and Z = 4. Compound 3 crystallizes in the triclinic P1 space group with a = 11.2183(6) [Angstrom], b = 14.2551(8) [Angstrom], c = 16.629(1) [Angstrom], [alpha] = 79.326(1)[degrees], [beta] = 73.605(1)[degrees], [gamma] = 75.496(1)[degrees], V = 2451.0(2) [Angstrom].sup.3], Z = 2. Compound 4 crystallizes in the monoclinic [P2.sub.1]/n space group with a = 13.1148(9) [Angstrom], b = 27.128(2) [Angstrom], c = 14.882(1) [Angstrom], [beta] = 114.056(2)[degrees], V = 4834.8(6) [[Angstrom].sup.3], Z = 4. The magnetic properties of compounds 1-4 were studied over the 2-300 K temperature range. Compounds 1 and 2 with monometallic [Ni[(NCS).sub.4]].sup.2-] complex units have similar magnetic properties, in agreement with nickel(II) ions in pseudo-tetrahedral environments. Compounds 3 and 4 with bimetallic [[[Ni.sub.2][(NCS).sub.8]].sup.4-] complex units exhibit magnetic properties, which are indicative of Ni(II)-Ni(II) ferromagnetic interactions with zero-field splitting effects caused by the pseudo-square-pyramidal or pseudo-trigonal-bipyramidal coordination environments of the nickel(II) ion in compounds 3 and 4, respectively. The structures and magnetic results for all compounds are correlated with NIR--UV--vis absorption spectra. Key words: nickel(II) thiocyanato complexes, crystal structures, paramagnetism, molecular magnetism, exchange coupling, absorption spectroscopy.

Surface plasmons were accessed with mid-IR light using zeroth-order FTIR transmission spectra. It is reported that these can be used in sensitive detection schemes.

A computational kinetic Monte Carlo (KMC) experiments that examines the time scale and pathways of H-atom mobility across the step edges connecting (100), (110), and (111) surfaces and the time-scale and pathway of H-atom penetration in the sublayer of the surfaces is reported. The activation energies for H mobility from site-to-site using a realistic potential energy function are also determined.

An analogous phenomenon for the azide complexes for nickel (II) is described. The thermodynamic and kinetic parameters of the studied redox system are determined by a comparison of the experimental and theoretical dependencies.

Temperature program desorption (TPD) and X-ray photoelectron spectroscopy (XPS) were used to study the adsorption and thermal reactions of 2-iodoethanol on clean Ni(100) single crystal surfaces. The absence of significant production of acetaldehyde from adsorbed ethanol results in the hydrogenation of the oxametallacycle to ethoxide.

The synthesis of a series of (alpha-diimine) NiR(sub 2)(R=Et, 9super n) Pr) complexes via grignard alkylation of the corresponding (alpha-diimine)NiBr(sub 2) precursors is presented. Trapping of these complexes with ethylene provides cationic Ni alkyl ethylene species, which are used to determine rates of ethylene insertion into primary and secondary carbon centers.

The structural confinement effects of amorphous ternary chalcogenide of Ni(SbTe3)(sub 2) in mesoporous channels of different pore diameters were studied. The structural confinement causes the suppression of photon coupling to the photoexcited carriers in the ternary chalcogenide incorporated in aluminosiliceous host (AlMCM-41).

A study is conducted to examine the hydrogenation of benzene to cyclohexadiene on a Ni(111) surface with the help of ab-initio local-density-functional calculations. A detailed analysis of the structural and electronic properties of the molecule at the corresponding transition states is described.

Electrochemical impedance spectroscopy measurements under a small alternating current density were performed to investigate electrochemical reactions on (110) single-crystalline nickel surfaces in nickel sulfamate electrolyte. The reaction impedance shows a power law of the ac modulation frequency, and two exponents for the reaction resistance and reaction capacitance are found to approximately agree with values predicted by a homogeneous charge-transfer reaction mode.

Ab initio included cluster UMP2 computations are conducted on paramagnetic 3d(super 9) cis-[Ni(CN)(sub 4)Cl(sub 2)](super 5-) cluster in KCl host lattice considering short and long-range crystal reactions. Origination of hyperfine interactions primarily from spin polarization of the valence orbitals caused by the unpaired electron is demonstrated.

A detailed study of the properties of the porosity found in the methanol-templated phase Ni(sub 2)(4,4'-bipyridine)3(NO3)4 is discussed. Mechanisms for the transformation are proposed which require breaking of at least one in six of the covalent bonds that confer rigidity on the framework.

A new quasi-one-dimensional compound Ni8Bi8SI is synthesized and its crystal structure determined from single-crystal x-ray diffraction data. Analysis of chemical bonding reveals strong multicenter Ni-Bi bonds and pair Ni-S interactions within the compound.

A number of bimetallic complexes of Ni(II) and Cu-(II) of the type is isolated and characterized. The four ligands are used were bis-amines of\r bis-imines and with both di- or trimethylene links between the nonaromatic nitrogen atoms.

A report is presented on the extension of the structural concept to the solid state organization of anionic square-planar nickel dithiolene complexes. The preparation of monoanionic, paramagnetic complex and analysis of its crystal structure in relation to its magnetic behavior is also reported.

A hypothesis is conducted to explain the difference between catalytic activity of nickel complexes and the dppe concerns of autoionization equilibrium. The method used in this study is the reductive splitting of tris(o-methoxyphenyl) phosphane (P(o-MeO-Ph)sub3) using sodium in ammonia.