Nickel Carbonyl Research Articles

A highly active Ni/mesoporous attapulgite for hydrocracking C[sbnd]O bonds in rice straw

A novel linear core–shell structured mesoporous silica coated microfiber attapulgite (MPSCMFA) was prepared. Ni/MPSCMFA, i.e., MPSCMFA-supported nickel catalyst was subsequently prepared by thermally decomposing nickel tetracarbonyl on MPSCMFA. Benzyloxybenzene (BOB) was used as a related model compound to evaluate the catalytic activity of Ni/MPSCMFA for CO bond cleavage. As a result, BOB was completely converted to toluene and phenol under pressurized hydrogen at 150°C over Ni/MPSCMFA, suggesting that Ni/MPSCMFA is highly active for hydrocracking the CO bond in BOB at low temperatures. Ni/MPSCMFA-catalyzed hydroconversion of rice straw powder (RSP) was also investigated. The results show that the resulting soluble portion (SP) has higher contents of carbon and hydrogen, but lower content of oxygen than RSP. Especially, C4–C9 alkanols are the dominant compounds in the SP (up to 70.77%).

Improved performance of Fe-Ni-S/γ-AlOOH for catalytic hydrocracking of di(1-naphthyl)methane

Supported iron sulphides, nickel sulphides, and iron-nickel sulphides were prepared using iron pentacarbonyl, nickel tetracarbonyl, and sulphur as precursors and γ-AlOOH as the support under different conditions, including temperature, active species and their loading sequence. Their activities for catalytic hydrocracking of di(1-naphthyl)methane (DNM) were examined at 300°C. As for the catalysts prepared at optimum temperature, Ni-S/γ-AlOOH is more active for DNM hydrocracking than Fe-S/γ-AlOOH. According to observation of SEM micrographs, Fe-Ni-S/γ-AlOOH has higher thermal stability to resist the metal particle agglomeration compared to Fe-S/γ-AlOOH.

Metal Carbonyl Vapor Generation Coupled with Dielectric Barrier Discharge To Avoid Plasma Quench for Optical Emission Spectrometry

The scope of dielectric barrier discharge (DBD) microplasma as a radiation source for optical emission spectrometry (OES) is extended by nickel carbonyl vapor generation. We proved that metal carbonyl completely avoids the extinguishing of plasma, and it is much more suitable for matching the DBD excitation and OES detection with respect to significant DBD quenching by concomitant hydrogen when hydride generation is used. A concentric quartz UV reactor allows sample solution to flow through the central channel wherein to efficiently receive the uniformly distributed UV irradiation in the confined cylindrical space between the concentric tubes, which facilitates effective carbonyl generation in a nickel solution. The carbonyl is transferred into the DBD excitation chamber by an argon stream for nickel excitation, and the characteristic emission of nickel at 232.0 nm is detected by a charge-coupled device (CCD) spectrometer. A 1.0 mL sample solution results in a linear range of 5-100 μg L(-1) along with a detection limit of 1.3 μg L(-1) and a precision of 2.4% RSD at 50 μg L(-1). The present DBD-OES system is validated by nickel in certified reference materials.

A Reactive Intermediate, [Ni5(C6H4N3)6(CO)4], in the Formation of Nonameric Clusters of Nickel, [Ni9(C6H4N3)12(CO)6] and [Ni9(C6H4N3)12(CO)6].2(C3H7NO)

Three new molecular compounds, [Ni5(bta)6(CO)4], I, [Ni9(bta)12(CO)6], II, [Ni9(bta)12(CO)6]. 2(C3H7NO), III, (bta = benzotriazole) were prepared employing solvothermal reactions. Of these, I have pentanuclear nickel, whereas II and III have nonanuclear nickel species. The structures are formed by the connectivity between the nickel and benzotriazole giving rise to the 5- and 9-membered nickel clusters. The structures are stabilised by extensive π…π and C-H... π interactions. Compound II and III are solvotamorphs as they have the same 9-membered nickel clusters and have different solvent molecules. To the best of our knowledge, the compounds I–III represent the first examples of the same transition element existing in two distinct coordination environment in this class of compounds. The studies reveal that compound I is reactive and could be an intermediate in the preparation of II and III. Thermal studies indicate that the compounds are stable upto 350∘C and at higher temperatures (∼ 800∘C) the compounds decompose into NiO. Magnetic studies reveal that II is anti-ferromagnetic. Nickel carbonyl compounds containing five and nine nickel centers have been synthesized and structurally characterized. Pentamer nickel compound transforms to the nonamer compounds as a function of time and temperature.

A DFT + Umol model study of the self-interaction error in standard density functional calculations of Ni(CO) m (m = 1–4)

The trend in the first ligand dissociation energies of the subcarbonyl and carbonyl complexes Ni(CO) m , m = 1–4, is a typical example for consequences of the self-interaction error in calculations using semi-local density functional approximations. The self-interaction effects on bond lengths and ligand dissociation energies are examined with the DFT + Umol approach, an extension of the DFT + U method to molecular orbitals. A detailed analysis shows that (1) the Ni 3d subshell is most affected by self-interaction and (2) the +Umol correction on the CO 2π* orbitals has no major positive effect on the nickel carbonyl complexes, at variance with similar models for the CO adsorption on surfaces of transition metals.

Reversible CO binding enables tunable CO/H₂ and CO/N₂ separations in metal-organic frameworks with exposed divalent metal cations.

Six metal-organic frameworks of the M2(dobdc) (M = Mg, Mn, Fe, Co, Ni, Zn; dobdc(4-) = 2,5-dioxido-1,4-benzenedicarboxylate) structure type are demonstrated to bind carbon monoxide reversibly and at high capacity. Infrared spectra indicate that, upon coordination of CO to the divalent metal cations lining the pores within these frameworks, the C-O stretching frequency is blue-shifted, consistent with nonclassical metal-CO interactions. Structure determinations reveal M-CO distances ranging from 2.09(2) Å for M = Ni to 2.49(1) Å for M = Zn and M-C-O angles ranging from 161.2(7)° for M = Mg to 176.9(6)° for M = Fe. Electronic structure calculations employing density functional theory (DFT) resulted in good agreement with the trends apparent in the infrared spectra and crystal structures. These results represent the first crystallographically characterized magnesium and zinc carbonyl compounds and the first high-spin manganese(II), iron(II), cobalt(II), and nickel(II) carbonyl species. Adsorption isotherms indicate reversible adsorption, with capacities for the Fe, Co, and Ni frameworks approaching one CO per metal cation site at 1 bar, corresponding to loadings as high as 6.0 mmol/g and 157 cm(3)/cm(3). The six frameworks display (negative) isosteric heats of CO adsorption ranging from 52.7 to 27.2 kJ/mol along the series Ni > Co > Fe > Mg > Mn > Zn, following the Irving-Williams stability order. The reversible CO binding suggests that these frameworks may be of utility for the separation of CO from various industrial gas mixtures, including CO/H2 and CO/N2. Selectivities determined from gas adsorption isotherm data using ideal adsorbed solution theory (IAST) over a range of gas compositions at 1 bar and 298 K indicate that all six M2(dobdc) frameworks could potentially be used as solid adsorbents to replace current cryogenic distillation technologies, with the choice of M dictating adsorbent regeneration energy and the level of purity of the resulting gases.

Nanoparticle growth in supported nickel catalysts during methanation reaction--larger is better.

A major cause of supported metal catalyst deactivation is particle growth by Ostwald ripening. Nickel catalysts, used in the methanation reaction, may suffer greatly from this through the formation of [Ni(CO)4 ]. By analyzing catalysts with various particle sizes and spatial distributions, the interparticle distance was found to have little effect on the stability, because formation and decomposition of nickel carbonyl rather than diffusion was rate limiting. Small particles (3-4 nm) were found to grow very large (20-200 nm), involving local destruction of the support, which was detrimental to the catalyst stability. However, medium sized particles (8 nm) remained confined by the pores of the support displaying enhanced stability, and an activity 3 times higher than initially small particles after 150 h. Physical modeling suggests that the higher [Ni(CO)4 ] supersaturation in catalysts with smaller particles enabled them to overcome the mechanical resistance of the support. Understanding the interplay of particle size and support properties related to the stability of nanoparticles offers the prospect of novel strategies to develop more stable nanostructured materials, also for applications beyond catalysis.

Photochemical vapor generation for removing nickel impurities from carbon nanotubes and its real-time monitoring by atomic fluorescence spectrometry

A new method was proposed to remove trace nickel catalyst impurities from carbon nanotube (CNT) materials by the use of UV-induced photochemical carbonyl generation, and the process was real-time monitored by atomic fluorescence spectrometry. The CNTs were purified under mild optimal experimental conditions, and the characteristics of the purified CNTs were kept well. After purification, the content of nickel in the CNT materials was reduced from 1% to 0.4%, with a removal efficiency of 60%. The produced volatile nickel carbonyl was separated and introduced into an argon/hydrogen flame atomizer-atomic fluorescence spectrometer for measuring nickel atomic fluorescence signal to real-time monitor the purification process.

The changes of serum nickel levels in rats with acute nickel carbonyl poisoning

Objective To master the serum nickel change rule of acute nickel carbonyl poisoning in rats,and to provide laboratory support for clinical treatment of acute nickel carbonyl poisoning patients.Methods SPF rats were given nickel carbonyl (250mg/m3,500mg/m3) in static inhalation for 30min.Rats were anesthetized by ether for 15 seconds after exposure for 30min,2h,4h,8h,12h,24h,48h,72h and 7d respectively.Anatomized rats,kept blood collection 2-3mL,and separated serum 0.5-1mL.Serum nickel was detected by AA800 (American PE company).Results The average serum nickel levels of 250mg/m3 dose group at 30min,2h,4h,8h,12h,24h,48h,72h,7d were (33.69 ±2.59),(24.61 ±3.03),(27.83 ±5.69),(21.36 ±4.14),(20.39 ±4.14),(18.80 ±7.02),(14.51 ±8.21),(13.58 ± 5.78) and (12.83 ± 4.41)μg/L.30 minutes reached the peak,and was 5.30-fold of those in normal controls.There had significant differences compared with normal control(t =5.959,5.958,5.990,5.998,5.997,5.994,5.990,4.317,4.347,all P ＜ 0.01).The average serum nickel levels of 500mg/m3 dose group at 30min,2h,4h,8h,12h,24h,48h,72h,7d were (72.22 ± 1.62),(57.78 ± 12.99),(42.25 ± 7.25),(103.77 ± 11.11),(79.04 ±12.26),(26.35 ±6.56),(18.58 ±4.92),(17.22 ±9.73),(14.59 ±5.27) μg/L.8h reached the peak,and was 16.33-fold of normal controls.The differences were significant (t =5.960,5.947,5.978,5.927,5.948,5.959,3.143,2.447,2.440,all P ＜ 0.05).Meanwhile,there were significant differences between two groups of 30min,2h,4h,8h,12h(t =5.208,2.447,2.449,5.959,5.959,P =0.001,0.049,0.042,0.000,0.000),but there was no significant difference after 24h.Conclusion There was significant doses-effect relationship between serum nickel content of acute nickel carbonyl poisoning rats and the dosage.Nickel carbonyl or its metabolites were excreted mainly within 24h. Key words: Carbonyl nickel; Serum nickel

Transmethylation of a four-coordinate nickel(i) monocarbonyl species with methyl iodide

The reaction of a nickel(i) carbonyl species with CH3I revealed the formation of (PNP)NiCOCH3 which differs from its zerovalent congener.

Influence of preparation method on supported Cu–Ni alloys and their catalytic properties in high pressure CO hydrogenation

Silica supported Cu–Ni (20 wt% Cu + Ni on silica, molar ratio of Cu/Ni = 2) alloys are prepared via impregnation, coprecipitation, and deposition–coprecipitation methods. The approach to co-precipitate the SiO2 from Na2SiO3 together with metal precursors is found to be an efficient way to prepare high surface area silica supported catalysts (BET surface area up to 322 m2 g−1, and metal area calculated from X-ray diffraction particle size up to 29 m2 g−1). The formation of bimetallic Cu–Ni alloy nanoparticles has been studied during reduction using in situ X-ray diffraction. Compared to impregnation, the coprecipitation and deposition–coprecipitation methods are more efficient for preparation of small and homogeneous Cu–Ni alloy nanoparticles. In order to examine the stability of Cu–Ni alloys in high pressure synthesis gas conversion, they have been tested for high pressure CO hydrogenation (50 bar CO and 50 bar H2). These alloy catalysts are highly selective (more than 99 mol%) and active for methanol synthesis; however, loss of Ni caused by nickel carbonyl formation is found to be a serious issue. The Ni carbonyl formation should be considered, if Ni-containing catalysts (even in alloyed form) are used under conditions with high partial pressure of CO.

Recyclable Decoration of Amine-Functionalized Magnetic Nanoparticles with Ni2+ for Determination of Histidine by Photochemical Vapor Generation Atomic Spectrometry

It is critically important to accurately determine histidine since it is an indicator for many diseases when at an abnormal level. Here, an inexpensive and simple method using an amine-functionalized magnetic nanoparticle-based Ni(2+)-histidine affinity pair system was developed for highly sensitive and selective detection of histidine in human urine by photochemical vapor generation atomic spectrometry. Ni(2+) was first bound to the amine groups of the amine-functionalized magnetic nanoparticles and then liberated to solution via the highly specific interaction between the histidine and Ni(2+) in the presence of histidine. The liberated histidine-Ni(2+) complex was exposed to UV irradiation in the presence of formic acid to form gaseous nickel tetracarbonyl, which was separated from the sample matrix and determined by atomic absorption/fluorescence spectrometry. Compared to other methods, this approach promises high sensitivity, simplicity in design, and convenient operation. The need for organic solvents, enzymatic reactions, separation processes, chemical modification, expensive instrumentations, and sophisticated and complicated pretreatment is minimized with this strategy. A limit of detection of 1 nM was obtained and provided tens-to-hundreds of fold improvements over that achieved with conventional methods. The protocol was evaluated by analysis of several urine samples with good recoveries and showed great potential for practical application.

Kinetic Monte Carlo modeling of reaction-induced phase separation in Au/Ni(111) surface alloy

Kinetic Monte Carlo (KMC) simulations of Au–Ni phase separation in Au/Ni(111) surface alloy during nickel carbonyl formation reaction were performed at room temperature by taking into account realistic rates of Au and Ni adatom diffusion and CO adsorption and desorption, while keeping the rate of nickel carbonyl formation reaction as a free parameter. We also obtained pair and three-body interaction constants between Au and Ni adatoms using the ab initio calculations and demonstrated that their proper choice is crucial for understanding the Au–Ni separation process. Three regimes with qualitatively different Ni–CO reaction propagation kinetics in Au/Ni(111) surface alloy were found by varying the constants of trio-triangle interactions within the limits of their accuracy. The sensitivity of the proposed model to interaction parameters leads to the regimes that differ by step flow rate, Au islands formation mechanism (channel-type or homogenous flow), Au island contamination level by Ni impurities and reaction damping tendency at the reaction front. Nucleation of nickel-free Au islands was observed for a homogeneous step flow pattern, and the corresponding step flow rate is in a good quantitative agreement with existing experimental data.

Steric and Electronic Parameters of a Bulky yet Flexible N-Heterocyclic Carbene: 1,3-Bis(2,6-bis(1-ethylpropyl)phenyl)imidazol-2-ylidene (IPent)

The free N-heterocyclic carbene IPent (1; IPent = 1,3-bis(2,6-bis(1-ethylpropyl)phenyl)imidazol-2-ylidene) was prepared from the corresponding imidazolium chloride salt (2). The steric and electronic parameters of 1 were determined by synthesis of the gold(I) chloride complex [Au(IPent)Cl] (3) and the nickel–carbonyl complex [Ni(IPent)(CO)3] (4), respectively. 3 and 4 were fully characterized by NMR spectroscopy, elemental analysis, and X-ray diffraction studies on single crystals.

ChemInform Abstract: The Chemistry of Group‐VIb Metal Carbonyls

AbstractReview: 296 refs.

Acoustic nickel carbonyl assay – proof of principle

In the Mond process, impure nickel is converted to nickel carbonyl by exposure to carbon monoxide at about 70 °C which is, in turn, decomposed back to nickel at about 200 °C. The decomposition reaction can be made to happen on the surface of a sensor where the rate of nickel deposition is used to calculate the concentration of nickel carbonyl in the gas sample. A novel heated sensor based on an SC cut quartz thickness shear mode acoustic resonator operating at 18 MHz with one electrode acting as a thin film heating element has been demonstrated to be capable of quantitatively detecting nickel carbonyl at 6 parts per billion in a timely manner.

Enhanced low-temperature activity of CO2 methanation over highly-dispersed Ni/TiO2 catalyst

The sustainable development of carbon recycling has attracted considerable attention from the viewpoint of the environment and resources. Herein, Ni nanoparticles (NPs) immobilized on a TiO2 support were synthesized via a deposition–precipitation method followed by a calcination–reduction process (denoted as Ni/TiO2-DP), which can be used as a promising heterogeneous catalyst towards CO2 methanation. Transmission electron microscope (TEM) images show that Ni NPs are highly dispersed on the TiO2 surface (particle size: 2.2 nm), with a low Ni–Ni coordination number revealed by the hydrogen temperature programmed desorption (H2-TPD) and extended X-ray absorption fine structure (EXAFS) techniques. Moreover, the catalyst with a Ni loading of 15 wt% exhibits excellent catalytic behavior towards CO2 methanation (conversion: 96%; selectivity: 99%) at a reaction temperature as low as 260 °C. The good dispersion of Ni NPs with large unsaturation facilitates a high exposure of active sites, which accelerates the formation of surface-dissociated hydrogen and the subsequent hydrogenation removal of surface nickel carbonyl species, accounting for the resulting enhanced low-temperature catalytic performance.

Infrared photodissociation spectra of mass selected homoleptic nickel carbonyl cluster cations in the gas phase

Infrared spectra of mass-selected homoleptic nickel carbonyl cluster cations including dinuclear Ni2(CO)7(+) and Ni2(CO)8(+), trinuclear Ni3(CO)9(+) and tetranuclear Ni4(CO)11(+) are measured via infrared photodissociation spectroscopy in the carbonyl stretching frequency region. The structures are established by comparison of the experimental spectra with simulated spectra derived from density functional calculations. The Ni2(CO)7(+) cation is characterized to have an unbridged asymmetric (OC)4Ni-Ni(CO)3(+) structure with a Ni-Ni single bond. The Ni2(CO)8(+) cation has a Ni-Ni half-bonded D3d structure with both nickel centers exhibiting an 18-electron configuration. The trinuclear Ni3(CO)9(+) cluster cation is determined to have an open chain like (OC)4Ni-NiCO-Ni(CO)4 structure. The tetranuclear Ni4(CO)11(+) cluster cation is determined to have a tetrahedral structure with two-center and three-center bridge-bonded carbonyl units. These nickel carbonyl cluster cations all involve trigonal pyramid like Ni(CO)4 building blocks that satisfy the 18-electron configuration of the nickel centers.

Density Functional Study on the Mechanism of Nickel-Mediated Diazo Carbonylation

The mechanism of diazo activation as well as the carbonylation of the resulting carbene complexes has been investigated by means of DFT calculations at the PBE0/TZVP level of theory. The free energy profile of all elementary steps of the reaction, i.e., diazo coordination, dinitrogen extrusion, carbene–CO coupling, CO coordination, and ketene elimination, have been elucidated for diazomethane and ethyl diazoacetate as substrates and for Ni(CO)3, Ni(CO)2(PH3), and Ni(dtbpe)(CO) (dtbpe = 1,2-bis(di-tert-butylphosphino)ethane) as precursors. The reaction rate is determined by the formation of the coordinatively unsaturated precursor followed by the dinitrogen extrusion, regardless of the initial diazo compound and the catalyst precursor. For the homoleptic precursor Ni(CO)3 the free energy of activation for diazomethane and ethyl diazoacetate (EDA) is 16.9 and 22.4 kcal/mol, respectively. The replacement of one carbonyl ligand with PH3 results in a decrease in the activation barrier, modifying the energies to 15.7 and 20.5 kcal/mol, respectively. The activation free energy of the diazo extrusion step promoted by Ni(dtbpe)(CO) is 24.3 kcal/mol for diazomethane and 28.1 kcal/mol for EDA. The formation of carbene complexes is slightly endergonic starting from the homoleptic precursor and exergonic for the phosphine-substituted complex. The carbene–CO coupling, resulting in coordinatively unsaturated ketene complexes, is a fast and highly exergonic process with reaction free energies between −32.3 and −42.1 kcal/mol, depending on the substituents. Under a carbon monoxide atmosphere the ketene complexes may uptake one CO, forming coordinatively saturated ketene complexes via low barriers in exergonic reactions. The final step, i.e., the dissociation of ketene or ethoxycarbonylketene from the saturated ketene complex, regenerates the corresponding nickel–carbonyl precursor. The azine formation side reaction for the simplest case between Ni(CO)3 and diazomethane has been also examined and found to be highly exergonic; however, the large free energy barrier prevents the formation of benzophenone-azine when CO is also present.

The chemistry of group-VIb metal carbonyls

The special interest attached to the chemistry of metal carbonyls arises from several causes. While quite distinct from the metal carbonyls in the organometallic compounds, they differ in physical properties (e.g., their volatility) from all other compounds of the transition metals. Chemically, they constitute a group of compounds in which the formal valency of the metal atoms is zero, and in this respect (apart, perhaps, from the ammoniates of the alkali metals) they are comparable only with the recently discovered compounds. As a class, the carbonyls are reactive compounds, and a number of new types of inorganic compounds have been discovered. In the concepts for new products, performance, product safety, and product economy criteria are equally important. They are taken into account already when the raw material base for a new industrial product development is defined. Since the discovery of nickel carbonyl by Mond and Langer in 1888, the carbonyls of the iron group and of chromium, molybdenum and tungsten have found important technical applications, e.g., in the Mond nickel process, and for the preparation of the metals in a state of subdivision and of purity suitable for powder metallurgy, for catalysts, etc. The reaction mechanism of the processes developed for producing the carbonyls technically has only recently received its interpretations. Within the space of review it is necessary to limit discussion to a few topics. Particular stress has accordingly laid upon (a) the chemical bonding in metal carbonyls, (b) importance of IR and NMR spectroscopy in characterization of metal carbonyls, (c) substitution reactions of G-VIb metal carbonyls, (d) kinetics and mechanism of substitution reactions in metal carbonyls, (e) substituted complexes of G-VIb metal carbonyl, (f) chelate complexes of G-VIb metal carbonyls, (g) uses of G-VIb metal carbonyl complexes and (h) studies done on G-VIb metal carbonyls.