Nickel Carbonyl Research Articles

The reactivity of N-heterocyclic germylenes and stannylenes based on 9,10-phenanthrendiimines towards metal carbonyls and sulfur

The reactivity of germylene and stannylene based on 9,10-phenanthrenediimine are described. Complexes of nickel and iron carbonyls with a coordinated germylene were obtained in good yields under mild conditions. The abilities of germylene to be involved in oxidative addition reactions with preserving of N-heterocycle were demonstrated in reactions with dithio-bis(tricarbonyliron) and elemental sulfur. All the compounds were characterized structurally by X-ray diffraction analysis.

Chasing the Mond Cation: Synthesis and Characterization of the Homoleptic Nickel Tetracarbonyl Cation and its Tricarbonyl-Nitrosyl Analogue.

130 years after Mond discovered the first homoleptic carbonyl complex Ni(CO)4, we report on a [Ni(CO)4].+ salt as the first synthesis of any homoleptic nickel carbonyl cation in the condensed phase. It was prepared by oxidation of nickel metal with the synergistic oxidant Ag[F{Al(ORF)3}2]/0.5 I2 (RF=C(CF3)3) in CO atmosphere. This D2d‐symmetric metalloradical represents the last missing entry among the structurally characterized homoleptic carbonyl cations of Groups 6 to 11. Additionally, the nickel tricarbonyl‐nitrosyl cation [Ni(CO)3(NO)]+ was obtained by usage of NO[F{Al(ORF)3}2] and all products were fully characterized by means of IR, Raman, NMR/EPR, single crystal and powder XRD.

Chasing the Mond Cation: Synthesis and Characterization of the Homoleptic Nickel Tetracarbonyl Cation and its Tricarbonyl‐Nitrosyl Analogue

Abstract130 years after Mond discovered the first homoleptic carbonyl complex Ni(CO)4, we report on a [Ni(CO)4].+ salt as the first synthesis of any homoleptic nickel carbonyl cation in the condensed phase. It was prepared by oxidation of nickel metal with the synergistic oxidant Ag[F{Al(ORF)3}2]/0.5 I2 (RF=C(CF3)3) in CO atmosphere. This D2d‐symmetric metalloradical represents the last missing entry among the structurally characterized homoleptic carbonyl cations of Groups 6 to 11. Additionally, the nickel tricarbonyl‐nitrosyl cation [Ni(CO)3(NO)]+ was obtained by usage of NO[F{Al(ORF)3}2] and all products were fully characterized by means of IR, Raman, NMR/EPR, single crystal and powder XRD.

Analysis of Some Elements and Speciated Compounds in Fish Found in the New Calabar River of the Niger Delta Area, Nigeria

The flesh of guinean and blackchin tilapia, and mullet found in Choba river were collected for elemental studies of mercury, cadmium, lead, arsenic, nickel and speciated forms. Analytical method of X-ray fluorescence (XRF) was used for the elemental studies while Gas chromatographymass spectrometer (GC-MS) was used for the speciated forms. 4.3 mg/kg was the highest concentration of cadmium observed in blackchin tilapia. The three fish species all contained about 0.5 mg/kg of arsenic and 1 mg/kg of mercury. 1.7 mg/kg of lead was detected in mullet while 7.3 mg/kg of nickel was detected in blackchin tilapia. Organometallic compounds found were nickel tetracarbonyl, borane carbonyl in guinean tilapia, nickel tetracarbonyl, borane carbonyl and germanium(iv) pthalocyanine dichloride in blackchin tilapia and [µ-(ƞ6-benzene)] bis (ƞ5-2,4-cyclopentadien-yl) diµ-hydrodi-vanadium. Borane carbonyl was found in mullet.

A Simple Model for Gas-Phase Synthesis of Nickel Nanoparticles

Gas-phase synthesis of nickel (Ni) nanoparticles by thermal decomposition of nickel tetracarbonyl, Ni(CO)4, is simulated accounting for nucleation, surface growth, coagulation, and sintering. By detailed analysis of phenomenological expressions for sintering, it is shown that surface diffusion (SD) is the dominant sintering mechanism for Ni nanoparticles at low temperatures (T < 700 K) and early stages of sintering, but grain boundary diffusion (GBD) dominates as sintering progresses and at higher temperatures. This is consistent with molecular dynamics simulations of noble metal nanoparticle sintering. Using the average of the above SD and GBD characteristic sintering times for Ni as well as a monodisperse population balance model (MPBM) that accounts for agglomerate morphology, polydispersity, and evolving structure with scaling laws from mesoscale simulations, Ni agglomerate sintering is benchmarked with measurements of agglomerate mobility and primary particle diameters. The MPBM predictions are in good agreement with the measured concentration and sizes of Ni nanoparticles by thermal decomposition of Ni(CO)4 in a hot wall flow reactor.

CO2 methanation mechanism over Ni/Y2O3: an in situ diffuse reflectance infrared Fourier transform spectroscopic study.

Supported Ni catalysts are active in CO2 methanation. It is important to understand the reaction mechanism for the development of highly-active catalysts. In this study, we investigated the reaction pathways of CO2 methanation over Ni/Y2O3 and Ni/Al2O3 based on the adsorbates observed by diffuse reflectance infrared Fourier transform spectroscopy. For Ni/Al2O3, linear and bridged CO adsorbates were converted to nickel carbonyl hydride and/or formyl species, which would be further hydrogenated to methane. In contrast, the formation of formate adsorbates was specifically confirmed over Ni/Y2O3 under the CO2 methanation condition. The hydrogen molecule was activated by dissociatively-adsorbing on Ni particles. Then, the hydrogenation of formate adsorbates by the activated hydrogen species proceeded sequentially to form methane. The observed bridged CO species would not be a major intermediate for Ni/Y2O3.

Nickel(II) carbonyl, ammonia, and aceto-nitrile complexes supported by a pyridine dipyrrolide pincer ligand.

The synthesis, isolation and crystal structures of nickel(II) carbonyl, aceto-nitrile and ammonia complexes supported by a dianionic, pyridine dipyrrolide pincer ligand [pyrr2py]2-, namely, carbonyl[2,2'-(pyridine-2,6-di-yl)bis-(3,5-di-p-tolyl-pyrrolido-κN)]-nickel(II), [Ni(C41H33N3)(CO)], ammine[2,2'-(pyridine-2,6-di-yl)bis-(3,5-di-p-tolyl-pyrrolido-κN)]nickel(II), [Ni(C41H33N3)(NH3)], and (aceto-nitrile-κN)[2,2'-(pyridine-2,6-di-yl)bis-(3,5-di-p-tolyl-pyrrolido-κN)]nickel(II), [Ni(C41H33N3)(CH3CN)], as well as the free ligand 2,6-bis-(3,5-di-p-tolyl-pyrrol-2-yl)pyridine, C41H35N3 or [pyrr2py]H2 are reported. The nickel complexes are four-coordinate and adopt a square-planar geometry. The CO stretch of the nickel-bound carbon monoxide ligand of [pyrr2py]Ni(CO) has been observed at 2101 cm-1. The ammonia and aceto-nitrile complexes, [pyrr2py]Ni(NH3) and [pyrr2py]Ni(NCMe) feature all-nitro-gen coordination spheres around nickel consisting of different N-donor ligand types.

Nickel carbonyl formation in a fluidized bed reactor: experimental investigation and modeling

AbstractBACKGROUNDThe Mond process has been used in the industry for nickel purification over a century. However, theoretical studies on this process are few and primarily based on empirical models. In this article, experimental and theoretical modeling of nickel tetracarbonyl formation through the Mond process under different conditions in a fluidized bed reactor is presented. Nickel tetracarbonyl, known primarily as nickel carbonyl gas, is formed through the reaction between nickel powder and carbon monoxide. The apparent reaction rate is modeled as a function of reaction temperature, inlet gas pressure, and carbon monoxide flow rate. Experimental results were obtained using a fluidized bed reactor. A diffusion‐kinetics and a two‐phase bubbling bed model were developed to compare with experimental results. The reactor is considered as a differential flow reactor for the theoretical modeling.RESULTSRate of reaction is measured in a fluidized bed and used for the verification of the studied models. The best performing model is a kinetic‐diffusion model with a rate of reaction that obeys rem = Kem([CO])n, in which Kem is a function of mass transfer as well as kinetic variables, but is primarily temperature dependent. Also, n for low‐pressure and high‐pressures regions is −1 and −3, respectively.CONCLUSIONSThe reaction rate is strongly dependent on carbon monoxide gas pressure. The models developed are rather simple yet provide significant improvement in predictions of the reaction rate compared to the existing models in the literature. © 2020 Society of Chemical Industry

Catalytic hydroconversion of derivates from Naomaohu lignite over an active and recyclable bimetallic catalyst

Fe/attapulgite powder (AP), Ni/AP, and Fe-Ni/AP were prepared by thermally decomposing iron pentacarbonyl (IPC), nickel tetracarbonyl (NTC), and different molar ratios of IPC to NTC onto AP in ethoxyethane, respectively. Their activities for the catalytic hydrocracking of di(1-naphthyl)methane (DNM) were compared under the same conditions. As a result, the activity of Fe-Ni-S/AP (Fe:Ni = 2:1) for DNM hydrocracking is significantly higher than that of other catalysts used. DNM conversion is near 100% over Fe-Ni-S/AP with Fe:Ni = 2:1. Over the catalyst, H2 can be effectively split to H, which attacks the ipso-position of DNM to cleave the Car-Calk bridged bond in DNM. Naomaohu lignite was subjected to thermal dissolution/ethanolysis in ethanol to afford soluble portion 1 (SP1, yield 56.0%) and residue 1 (R1) followed by non-catalytic hydroconversion (NCHC) and catalytic hydroconversion (CHC) of SP1 and R1 at 300 °C using Fe-Ni-S/AP with Fe:Ni = 2:1 as the catalyst to afford SPNCHC, SPCHC, SP2 (yield 2.3%), and SPII (yield 11.2%). According to gas chromatography/mass spectrometric analysis, arenes are the most abundant in SPCHC, accounting for 21.9%, while the most abundant group component in SPNCHC are non‑nitrogen ketones, accounting for 20.0%.

Nickel Tetracarbonyl as Starting Material for the Synthesis of NHC‐stabilized Nickel(II) Allyl Complexes

A novel, useful in situ synthesis for NHC nickel allyl halide complexes [Ni(NHC)(η3‐allyl)(X)] starting from [Ni(CO)4], NHC and allyl halides is presented. The reaction of [Ni(CO)4] with (i) one equivalent of the corresponding NHC and (ii) with an excess of the corresponding allyl chloride at room temperature leads with elimination of carbon monoxide to complexes of the type [Ni(NHC)(η3‐allyl)(X)]. This approach was used to synthesize the complexes [Ni(tBu2Im)(η3‐H2C‐C(Me)‐CH2)(Cl)] (2), [Ni(iPr2ImMe)(η3‐H2C‐C(Me)‐CH2)(Cl)] (3), [Ni(iPr2Im)(η3‐H2C‐C(Me)‐CH2)(Cl)] (4), [Ni(iPr2Im)(η3‐H2C‐C(H)‐C(Me)2)(Br)] (5), [Ni(Me2ImMe)(η3‐H2C‐C(Me)‐CH2)(Cl)] (6), and [Ni(EtiPrImMe)(η3‐H2C‐C(Me)‐CH2)(Cl)] (7). The complexes 1 to 7 were characterized using NMR and IR spectroscopy and elemental analysis, and the molecular structures are provided for 2 and 7. The allyl nickel complexes 1–7 are stereochemically non‐rigid in solution due to (i) NHC rotation about the nickel‐carbon bond, (ii) allyl rotation about the Ni–η3‐allyl axis and (iii) π–σ–π allyl isomerization processes. The allyl halide complexes can be methylated as was demonstrated by the methylation of a number of the complexes [Ni(NHC)(η3‐allyl)(X)] with methylmagnesium chloride or methyllithium, which led to isolation of the complexes [Ni(Me2Im)(η3‐H2C‐C(Me)‐CH2)(Me)] (8), [Ni(tBu2Im)(η3‐H2C‐C(Me)‐CH2)(Me)] (9), [Ni(iPr2ImMe)(η3‐H2C‐C(Me)‐CH2)(Me)] (10), [Ni(iPr2Im)(η3‐H2C‐C(Me)‐CH2)(Me)] (11), [Ni(iPr2Im)(η3‐H2C‐C(H)‐C(Me)2)(Me)] (12), and [Ni(EtiPrImMe)(η3‐H2C‐C(Me)‐CH2)(Me)] (13). These complexes were fully characterized including X‐ray molecular structures for 10 and 11.

Quantifying the Electronic and Steric Properties of 1,3-Imidazole-Based Mesoionic Carbenes (iMICs)

1,3-Imidazole-based mesoionic carbenes (iMICs) are a very promising class of carbon-donor ligands in synthesis and catalysis. However, a systematic study of the quantification of stereoelectronic properties of iMICs is lacking. This is most likely due to the absence of rational synthetic routes to suitable iMIC compounds. Herein, we report the synthesis of the appropriate phosphinidene (iMICAr)PPh (iMICAr = :CCH(NDipp)2CAr; Ar = Ph (5a), DMP (5b); DMP = 4-Me2NC6H4; Dipp = 2,6-iPr2C6H3), selenium (iMICAr)Se (Ar = Ph (6a), DMP (6b)), and nickel carbonyl compounds (iMICAr)Ni(CO)3 (Ar = Ph (7a), DMP (7b)). The π-accepting property of iMICAr (Ar = Ph (2a), DMP (2b)) has been evaluated by 31P and 77Se NMR spectroscopic analyses of 5 and 6, respectively. The overall donor property of 2 has been assessed by determining the Tolman electronic parameter (TEP) of 7. Studies suggest that iMICAr (2) are stronger σ donors and weaker π acceptors compared to classical N-heterocyclic carbenes (NHCs). The steric profile of iMICAr (2) has been obtained by calculating the percentage buried volume (%Vbur) for (iMICAr)CuX (Ar = Ph, X = I (8a); Ar = DMP, X = Br (8b)).

Nickel addition to optimize the hydrogen storage performance of lithium intercalated fullerides

The addition of transition metals to alkali intercalated fullerides proved to enhance their already good hydrogen absorption properties. Herein we present a study based on two different synthetic strategies, allowing the addition of nickel as aggregates with different size to the lithium fulleride Li6C60: the former is based on the metathesis of nickel chloride, while the latter on the thermal decomposition of nickel carbonyl clusters. The hydrogen-storage properties of the obtained materials have been investigated with manometric and calorimetric measurements, which indicated a clear enhancement of the final absorption value and kinetics with respect to pristine Li6C60, as a consequence of nickel surface catalytic activity towards hydrogen molecules dissociation. We found up to 10 % increase of the total H2 weight % absorbed (5.5 wt% H2) in presence of Ni aggregates. Furthermore, the control of the transition metal particles size distribution allowed reducing the hydrogen desorption enthalpy of the systems.

Infrared + vacuum ultraviolet two-color ionization spectroscopy of neutral metal complexes based on a tunable vacuum ultraviolet free-electron laser.

This paper describes an experimental technique for studying neutral metal complexes using infrared + vacuum ultraviolet (IR+VUV) two-color ionization spectroscopy based on a tunable VUV free-electron laser (VUV-FEL). The preliminary IR spectroscopy results of mass-selected nickel tetracarbonyl are reported in this work. The results demonstrate that the tunable VUV-FEL light allows the selective ionization of a given neutral cluster free of confinement along with the recording of well-resolved IR spectra. As the ionization energies of many neutral clusters are accessible by a broadly tunable VUV-FEL (50-150 nm) and near-threshold ionization can be readily achieved, the proposed experimental method offers unique possibilities for the size-specific study of a wide variety of confinement-free neutral clusters.

Understanding the correlation between calcination temperature and performance in low‐temperature methanation over Ni‐Zr/Al2O3 catalysts

AbstractLow‐temperature methanation of CO in the continuous stirred tank reactor (CSTR) over Zr doped Ni/Al2O3 catalyst calcined at different temperatures (673, 723, and 823 K) was investigated. XRD, TPR, XPS, ICP, SEM, and S‐TPR techniques were employed to characterize the fresh and spent catalysts. Based on the characterization results, it was found that low‐temperature (673 K) calcination could effectively prohibit the formation of NiAl2O4 spinel, thereby resulting in more reducible NiO particles, which were the essential precursor of methanation active sites over the catalyst surface. Thus, the highest CO conversion of 93.6% was achieved over the 25N3ZA‐673 catalyst. In addition, the deactivation rate of 25N3ZA‐673 was relatively slow in comparison to 25N3ZA‐823 due to the presence of more reducible NiO. The formed nickel carbonyl species (Ni[CO]x), which quickly decomposed at a higher reaction temperature, was closely related to the catalyst deactivation. Therefore, 25N3ZA‐673 possessed much better stability at 593 K than that at 553 K.

Directional Catalytic Hydroconversion of Oxybis (methylene)dibenzene and an Extract from Piliqing Subbituminous Coal over a Magnetic Difunctional Solid Superbase

AbstractAn active and novel magnetic difunctional solid superbase catalyst Ni‐Mg2Si/attapulgite powder (AP) was prepared by thermally decomposing nickel tetracarbonyl onto the as‐synthesized Mg2Si/AP followed by impregnating Mg2Si onto AP in CCl4 and characterized by multiple analyses. It was also successfully used in the catalytic hydroconversion (CHC) of coal‐related model compound oxybis (methylene) dibenzene (OBMDB) and an extract (E) from Piliqing subbituminous coal (PSBC) in n‐hexane. As a result, OBMDB was completely converted to methylcyclohexane by the CHC under 3 MPa of initial hydrogen pressure at 240 °C for 2 h. Ni‐Mg2Si/AP can activate H2 to biatomic active hydrogen (H…H) and split H2 to immobile H+ attached on the Ni‐Mg2Si/AP surface and relatively mobile H−. Then the bridged linkage (BL) in OBMDB can be cleaved by H− attack on a α‐carbon atom in OBMDB, producing toluene and benzyloxy anion, which abstracts H+ from the Ni‐Mg2Si/AP surface to afford phenylmethanol (PM). The α‐carbon in PM is attacked by H‐ to generate toluene and HO−. H…H transfers to benzene ring in toluene yields methylcyclohexane. The soluble portion (SP) from the CHC (SPE‐CHC) and non‐CHC (NCHC) (SPE‐NCHC) of E were analyzed with a gas chromatograph/mass spectrometer and Fourier transform infrared spectrometer. Non‐substituted cycloalkanes (NSCAs) are predominant in the SPE‐CHC, accounting for 66.9 % of the total group components, and interestingly 65.3 % of NSCAs is cyclohexane, while non‐substituted arenes are the most abundant in the SPE‐NCHC. The results indicate that the CHC is beneficial to the fracture of COCBB and hydrogenation of ARs to produce more NSCAs.

Catalytic Hydroconversion of a High-Temperature Coal Tar over Two Attapulgite Powder-Supported Nickel Catalysts

Two attapulgite powder (AP)-supported nickel catalysts were prepared by thermally decomposing nickel tetracarbonyl onto AP in a laboratory (L-Ni/AP) and in a factory (F–Ni/AP). The Ni nanoparticles...

Unsaturated binuclear homoleptic nickel carbonyl anions Ni2(CO)n- (n = 4-6) featuring double three-center two-electron Ni-C-Ni bonds.

The homoleptic homodinuclear nickel carbonyl anions Ni2(CO)n- (n = 4-6) are mass-selected in the gas phase and examined with anion photoelectron velocity-map imaging spectroscopy combined with density functional calculations. The doubly carbonyl-bridged structures are found to be favorable for Ni2(CO)n- (n = 4-6). The nature of Ni-Ni bonding in these complexes is analysed with the aid of a range of state-of-the-art quantum chemistry methods. Despite the absence of direct multiple Ni-Ni bonds, the two nickel atoms in Ni2(CO)n- (n = 4-6) complexes are joined by two bridging carbonyl ligands via the sharing three-center two-electron Ni-C-Ni bond in turn to achieve the (16,16), (16,18), and eventually the favored (18,18) configurations.

Near ambient pressure adsorption of nickel carbonyl contaminated CO on Cu(111) surface

Formation of volatile nickel carbonyls with CO in catalytic reaction is one of the mechanisms of catalyst deactivation. CO is one of the most popular probe molecules to study the surface properties in model catalysis. Under ultra-high vacuum (UHV) conditions, the problem of nickel carbonyl impurity almost does not exist in the case that a high purity of CO is used directly. While in the near ambient pressure (NAP) range, nickel carbonyl is easily found on the surface by passing through the Ni containing tubes. Here, the NAP techniques such as NAP-X-ray photoelectron spectroscopy and NAP-scanning tunneling microscopy are used to study the adsorption of nickel carbonyl contaminated CO gas on Cu(111) surface in UHV and NAP conditions. By controlling the pressure of contaminated CO, the Ni-Cu bimetallic catalyst can form on Cu(111) surface. Furthermore, we investigate the process of CO adsorption and dissociation on the formed Ni-Cu bi-metal surface, and several high-pressure phases of CO structures are reported. This work contributes to understanding the interaction of nickel carbonyl with Cu(111) at room temperature, and reminds the consideration of CO molecules contaminated by nickel carbonyl especially in the NAP range study.

Enhanced hydrogenation of aromatic rings and hydrocracking of >Car[sbnd]O[sbnd] bridged bonds in the extraction residue from Piliqing subbituminous coal over a magnetic difunctional solid superbase

Ni-Mg2Si/attapulgite powder (AP) was prepared by thermally decomposing nickel tetracarbonyl onto the as-synthesized Mg2Si/AP by impregnating Mg2Si onto AP in CCl4. Its catalytic performance was evaluated by the catalytic hydroconversion (CHC) of oxydibenzene (ODB) in n-hexane under different reaction conditions. Both ODB conversion and cyclohexane selectivity are 100 % by the CHC of ODB over Ni-Mg2Si/AP under 3 MPa of initial hydrogen pressure at 240 °C for 4 h. However, almost no ODB was converted without Ni-Mg2Si/AP under the same conditions. The results show that Ni-Mg2Si/AP could activate H2 to biatomic active hydrogen (H⋯H) and H−, resulting in the hydrogenation of aromatic rings (ARs) and the hydrocracking of >CarO bridged bonds (COBBs), respectively. Additionally, the catalyst was also successfully applied in the CHC of extraction residue (ER) from Piliqing subbituminous coal (PSBC) in n-hexane. The group components of the soluble portion (SP) from CHC and non-CHC (NCHC) (SPCHC and SPNCHC) of ER were analyzed with a gas chromatograph/mass spectrometer. The yield (36.4 %) of SPCHC is significantly higher than that (1.8 %) of SPNCHC. More alkyl-substituted arenols (ASAs), anisoles, and methoxy-substitued cresols exist in SPNCHC, while SPCHC contains more normal alkanes (NAs), non-substituted cycloalkanes, alkylcyclohexanes, tetralins, and octahydroanthracenes. NAs are predominant in SPCHC, while ASAs are the most abundant in SPNCHC, indicating that the CHC facilitates the hydrocracking COBBs and hydrogenating ARs. ODB conversion is as high as 91.2 % after recycling 4 times. Therefore, the catalyst might be potential to produce coal-derived chemicals and clean liquid fuels to facilitate coal efficient conversions owing to its high activity, difunctionality, stability, and good recyclability.

Synthesis and Characterization of a N,C,N-Carbodiphosphorane Pincer Ligand and Its Complexes

The reaction of 2-pyridiyldiphenylphosphine (2) with tetrachloromethane and subsequent dehalogenation of the intermediate chloro phosphonium salt [(CDPPy2)Cl]Cl (3) with tris(1-pyrrolidyl)phosphine results in the formation of a new type of carbodiphosphorane N,C,N pincer ligand, sym-bis(2-pyridyl)tetraphenylcarbodiphosphorane, CDPPy2 (1). It crystallizes in a triclinic crystal system with a crystallographic point group of P1. This neutral double-ylidic N,C,N ligand is capable of stabilizing a wide range of metal coordination polyhedra, varying from square planar [(CDPPy2)PdCl]Cl (4), octahedral mer-[(CDPPy2)TiCl3] (5) and fac-[(CDPPy2)Cr(CO)3] (6) to trigonal-bipyramidal [(CDPPy2)MnCl2] (9) and [(CDPPy2)CoCl2] (10) complexes. Unprecedented dinuclear complexes are formed with molybdenum and nickel carbonyls. 1 reacts with [Mo(CO)3(NCMe)3] to form the symmetric κ3-N,C,N-[(CDPPy2)Mo(CO)3(μ-CO)Mo(CO)3] (7) with one bridging carbonyl next to a bridging central carbon atom with its two lone pairs. In contrast,...