Ni-O Bond Research Articles

Crystal structure of bis-{2-[(E)-(4-meth-oxy-lbenz-yl)imino-meth-yl]phenolato-κ(2) N,O (1)}nickel(II).

The asymmetric unit of the title compound, [Ni(C15H14NO2)2], comprises an Ni(II) cation, lying on an inversion centre, and a Schiff base anion that acts as a bidentate ligand. The Ni(II) cation is in a square-planar coordination environment binding to the imine N and phenolate O atoms of the two Schiff base ligands. The N- and O-donor atoms of the two ligands are mutually trans, with Ni-N and Ni-O bond lengths of 1.9191 (11) and 1.8407 (9) Å, respectively. The plane of the meth-oxy-benzene ring makes a dihedral angle of 84.92 (6)° with that of the phenolate ring. In the crystal, mol-ecules are linked into screw chains by weak C-H⋯O hydrogen bonds. Additional C-H⋯O hydrogen bonds, together with C-H⋯π contacts, arrange the mol-ecules into sheets parallel to the ac plane.

Origins of bad-metal conductivity and the insulator–metal transition in the rare-earth nickelates

For most metals, increasing temperature (T) or disorder will quicken electron scattering. This hypothesis informs the Drude model of electronic conductivity. However, for so-called bad metals this predicts scattering times so short as to conflict with Heisenberg's uncertainty principle. Here we introduce the rare-earth nickelates (RNiO_3, R = rare earth) as a class of bad metals. We study SmNiO_3 thin films using infrared spectroscopy while varying T and disorder. We show that the interaction between lattice distortions and Ni-O bond covalence explains both the bad metal conduction and the insulator-metal transition in the nickelates by shifting spectral weight over the large energy scale established by the Ni-O orbital interaction, thus enabling very low \sigma while preserving the Drude model and without violating the uncertainty principle.

Revealing the atomic and electronic structure of a SrTiO3/LaNiO3/SrTiO3 heterostructure interface

The atomic structures of SrTiO3 (STO)/LaNiO3 (LNO)/STO heterostructure interfaces were investigated by spherical aberration-corrected (CS) (scanning) transmission electron microscopy. Atomic displacement and lattice distortion measurements and electron energy loss spectroscopy (EELS) were used to quantitatively analyze the distortion of the interfacial octahedra and the bond length at the interfaces. Combined with high-resolution transmission electron microscopy (HRTEM) and scanning transmission electron microscopy analyses, two distinct interfacial atomic terminating layers are unambiguously determined. Ensuing quantitative HRTEM measurements revealed that the Ni-O bond length in the interfacial octahedral is elongated at the bottom interface (–NiO2-SrO–). Atomic displacement shows structural relaxation effects when crossing the interfaces and lattice distortions across the interface is more pronounced in LNO than in STO. The Ti/O atomic ratio, La and Ti relative atomic ratio as derived by EELS quantification indicate non-stoichiometric composition at the interfaces. Distinct fine structures of Ti-L2,3 edge and O-K edge at the bottom and top interfaces are observed. By comparison, we are able to estimate Ti valency at both interfaces. Combining the structural distortions and Ti valency, the polar discontinuity and charge transfer at the interfaces are discussed.

X-ray structure and spectroscopy of novel trans-[Ni(L)(NO3)2] and [Ni(L)](ClO4)2·2H2O complexes

Ni(L)(NO3)2 (complex 1) and [Ni(L)](ClO4)2⋅2H2O (complex 2) [L=3,14-diethyl-2,6,13,17-tetraazatricyclo(16.4.0.07,12)docosane] have been prepared and structurally characterized by single-crystal X-ray diffraction at 200K. For these constrained macrocycle complexes, nickel(II) exists in a distorted octahedral environment with the four nitrogen atoms of the macrocyclic ligands and two oxygen atoms from nitrate in axial positions in complex 1. The macrocyclic ligand in complex 1 adopts the most stable trans-III conformation. The Ni–N distances in both the complex 1 (2.094(4)–2.051(4)Å) and complex 2 (2.042(8)–1.996(7)Å), are typical but the axial ligands are coordinating, with NiO bond length, 2.198(3)Å for complex 1. The complex 2 adopts square planner geometry around the Ni(II) with four nitrogen atoms from macrocyclic ligand. The crystals are stabilized in a 3-D network by intra and intermolecular hydrogen bonds that are formed among the secondary nitrogen hydrogen atoms and nitrate in 1, and intermolecular hydrogen bonds are formed by perchlorate and NH groups in 2. The electronic absorption, IR and PL spectral properties are also discussed.

Nickel/zinc-catalyzed decarbonylative addition of anhydrides to alkynes: A DFT study

Density functional theory (DFT) was used to investigate the nickel- or nickel(0)/zinc- catalyzed decarbonylative addition of phthalic anhydrides to alkynes. All intermediates and transition states were optimized completely at the B3LYP/6-31+G(d,p) level. Calculated results indicated that the decarbonylative addition of phthalic anhydrides to alkynes was exergonic, and the total free energy released was -87.6 kJ mol(-1). In the five-coordinated complexes M4a and M4b, the insertion reaction of alkynes into the Ni-C bond occurred prior to that into the Ni-O bond. The nickel(0)/zinc-catalyzed decarbonylative addition was much more dominant than the nickel-catalyzed one in whole catalytic decarbonylative addition. The reaction channel CA→M1'→T1'→M2'→T2'→M3a'→M4a'→T3a1'→M5a1' →T4a1'→M6a'→P was the most favorable among all reaction pathways of the nickel- or nickel(0)/zinc- catalyzed decarbonylative addition of phthalic anhydrides to alkynes. And the alkyne insertion reaction was the rate-determining step for this channel. The additive ZnCl2 had a significant effect, and it might change greatly the electron and geometry structures of those intermediates and transition states. On the whole, the solvent effect decreased the free energy barriers.

Structure Studies on Order Assemblage of Nickel<sup> II</sup> Complexes

The nickelII complex [Ni (C9H9O3)2(H2O)2], Diaqua-bis (ethylvanillinato-O,O')-nickelII, the NiII atom is located on a twofold axis and is coordinated by two ethylvanillinate anions and two water molecule in a distorted octahedral geometry . The ethylvanillinate ligand chelates to the NiII atom through its ethyl and hydroxy O atoms,with greatly differing Ni-O bond distances (2.282(2) Å and 1.9792(16)Å). Adjacent complex link to each other via hydrogen bonds forming the three-dimensional supramolecular structure.

Bis(2,2′-bipyridyl-κ2N,N′)(sulfato-κ2O,O′)nickel(II) 2.5-hydrate

The title compound, [Ni(SO4)(C10H8N2)2]·2.5H2O, is a nickel(II) complex with a distorted octa­hedral coordination geometry. The NiII atom is bonded by two O atoms of the bidentate chelating sulfate ligand and the four N atoms of two chelating 2,2′-bi­pyridine ligands. The Ni—N bond lengths range from 2.059 (3) to 2.075 (3) Å and the Ni—O bond lengths are 2.098 (3) and 2.123 (3) Å. The bipyridyl ligands are both close to planar (r.m.s. deviations of 0.254 and 0.0572 Å) and are almost orthogonal, making a dihedral angle of 82.77 (1)°. In the crystal, the complex and water mol­ecules are connected by O—H⋯O hydrogen bonds. Inter­estingly, six water mol­ecules form a chain linking two complex mol­ecules via sulfate O atoms. There are also stacking inter­actions between the aromatic rings of neighbouring 2,2′-bi­pyridine ligands with shortest non-covalent contacts of 3.268 (6), 3.393 (6) and 3.435 (5) Å. One of the three unique water molecules shows half-occupation.

Nickel(II) 3,4;9,10-Perylenediimide bis-Phosphonate Pentahydrate: A Metal–Organic Ferromagnetic Dye

The new metal-organic compound nickel(II) 3,4;9,10-perylenediimide bis-phosphonate pentahydrate, i.e. Ni(2)[(PDI-BP)(H(2)O)(2)]·3H(2)O (1), has been synthesized and its structural and magnetic properties have been studied. Reaction of 3,4;9,10-perylenediimide bis-phosphonate (PDI-BP, hereafter) ligand and nickel chloride in water resulted in the precipitation of a red and poorly crystalline solid (1). As the solid shows a poor crystalline organization of aggregates, the energy dispersive X-ray diffraction analysis (EDXD) technique has been used to obtain short-range order structural information of the single nanoaggregates by radial distribution function analysis. The overall structure of the compound is characterized by layers containing perylene planes shifted in the direction perpendicular to the stacking axes in such a way that only the outer rings overlap. The edges of the perylene planes are connected to the phosphonate groups through an imido group. The oxygen atoms of the [-PO(3)](2-) group and those of the water molecules are bonded to the nickel ions resulting in a [NiO(6)] octahedral coordination sphere. The Ni-O bond lengths are 0.21 ± 0.08 nm and the Ni-O-Ni angles of aligned moieties are 95 ± 2°. The oxygen atoms of the water molecules and the nickel atoms are nearly planar and almost perpendicular to the perylene planes forming chains of edge-sharing octahedra. The magnetic properties of (1) show the presence of intrachain ferromagnetic Ni-Ni interactions and a long-range ferromagnetic order below 21 K with a canting angle and with a spin glasslike behavior due to disorder in the inorganic layer. Hysteresis cycles show a coercive field of ca. 272 mT at 2 K that decreases as the temperature is increased and vanishes at ca. 20 K.

Nickel-mediated hydrogenolysis of C-O bonds of aryl ethers: what is the source of the hydrogen?

Mechanistic studies of the hydrogenolysis of aryl ethers by nickel were undertaken with (diphosphine)aryl methyl ethers. A Ni(0) complex containing Ni-arene interactions adjacent to the aryl-O bond was isolated. Heating led to aryl-O bond activation and generation of a nickel aryl methoxide complex. Formal β-H elimination from this species produced a nickel aryl hydride which can undergo reductive elimination in the presence of formaldehyde to generate a carbon monoxide adduct of Ni(0). The reported complexes map out a plausible mechanism of aryl ether hydrogenolysis catalyzed by nickel. Investigations of a previously reported catalytic system using isotopically labeled substrates are consistent with the mechanism proposed in the stoichiometric system, involving β-H elimination from a nickel alkoxide rather than cleavage of the Ni-O bond by H(2).

Oxidative reforming of methane on structured Ni-Al2O3/cordierite catalysts

The catalytic properties of Ni/Al2O3 composites supported on ceramic cordierite honeycomb monoliths in oxidative methane reforming are reported. The prereduced catalyst has been tested in a flow reactor using reaction mixtures of the following compositions: in methane oxidation, 2–6% CH4, 2–9% O2, Ar; in carbon dioxide and oxidative carbon dioxide reforming of methane, 2–6% CH4, 6–12% CO2, and 0–4% O2, and Ar. Physicochemical studies include the monitoring of the formation and oxidation of carbon, the strength of the Ni-O bond, and the phase composition of the catalyst. The structured Ni-Al2O3 catalysts are much more productive in the carbon dioxide reforming of methane than conventional granular catalysts. The catalysts performance is made more stable by regulating the acid-base properties of their surface via the introduction of alkali metal (Na, K) oxides to retard the coking of the surface. Rare-earth metal oxides with a low redox potential (La2O3, CeO2) enhance the activity and stability of Ni-Al2O3/cordierite catalysts in the deep and partial oxidation and carbon dioxide reforming of methane. The carbon dioxide reforming of methane on the (NiO + La2O3 + Al2O3)/cordierite catalyst can be intensified by adding oxygen to the gas feed. This reduces the temperature necessary to reach a high methane conversion and does not exert any significant effect on the selectivity with respect to H2.

The role of the Auger parameter in XPS studies of nickel metal, halides and oxides

The critical role of the Auger parameter in providing insight into both initial state and final state factors affecting measured XPS binding energies is illustrated by analysis of Ni 2p(3/2) and L(3)M(45)M(45) peaks as well as the Auger parameters of nickel alloys, halides, oxide, hydroxide and oxy-hydroxide. Analyses of the metal and alloys are consistent with other works, showing that final state relaxation shifts, ΔR, are determined predominantly by changes in the d electron population and are insensitive to inter-atomic charge transfer. The nickel halide Auger parameters are dominated by initial state effects, Δε, with increasing positive charge on the core nickel ion induced by increasing electronegativity of the ligands. This effect is much greater than the final state shifts; however, the degree of covalency is reflected in the Wagner plot where the more polarizable iodide and bromide have greater ΔR. The initial state shift for NiO is much smaller than those of Ni(OH)(2) or NiOOH and the effective oxidation state is much less than that inferred from the average electronegativity of the ligand(s). Auger parameter analysis indicates that the bonding in NiO appears to have stronger contributions from initial state charge transfer from the oxygen ligands than that in the hydroxide and oxyhydroxide consistent with the considerable differences in the Ni-O bond lengths in these compounds with some relaxation of this state occurring during final state phenomena. The Auger parameter of NiOOH is, however, shifted positively, like the iodide, indicating greater polarizability of the ligands and covalency in this bonding. There is support for more direct use of relative bond lengths in interpreting differences between related compounds rather than more general electronegativity or similar parameters.

Bis{2-[(2-hydroxy-2-methylpropyl)iminomethyl]-4-nitrophenolato}nickel(II) dimethylformamide monosolvate

In the title compound, [Ni(C11H13N2O4)2]·C3H7NO, the NiII ion is octa­hedrally coordinated in an N2O4 environment by two identical Schiff base ligands. The Ni—O bond lengths range from 2.004 (2) to 2.106 (2) Å, while the Ni—N bond lengths are 2.038 (2) and 2.0465 (19) Å. The cis bond angles range from 78.64 (8) to 97.30 (8)°, with the former being due to the small bite of the amino­alcohol ligand, while the trans bond angles range from 167.86 (8) to 171.23 (8)°. One of the alcohol H atoms forms a hydrogen bond with the dimethyl­formamide (DMF) solvent mol­ecule, while the other links mol­ecules into chains along the b axis through inter­molecular O—H⋯O hydrogen bonds. There are bifurcated C—H⋯O inter­actions involving one of the nitro groups between parallel stacks of mol­ecules in the b-axis direction.

N 2O decomposition over K-promoted NiAl mixed oxides derived from hydrotalcite-like compounds

NiAl mixed oxides derived from hydrotalcite-like compounds (HLCs) with Ni/Al molar ratio of 4.1 were incipiently impregnated by potassium carbonate solution to prepare K-promoted NiAl mixed oxide catalysts with K/Ni molar ratio in the range of 0.05 to 0.2, and applied in catalytic decomposition of N 2O. The catalysts were characterized by ICP-AES, XRD, BET, H 2-TPR, XPS techniques, and their catalytic activities for N 2O decomposition were tested. The results show that the catalytic activity of NiAl mixed oxide impregnated by K 2CO 3 solution is much higher than that of NiAl mixed oxide without K species and superior to the catalyst prepared by fresh NiAl-HLC impregnated using K 2CO 3 solution. The effect of K loadings and calcination temperatures of catalysts on catalytic activity has been investigated. It is found that the catalytic activity of NiAl mixed oxide, especially the one with K/Ni=0.1 and calcinated at 400°C, is largely enhanced by the addition of K species in the presence of oxygen and/or steam. XPS and H 2-TPR results show that the electron binding energy of surface active NiO species in K-promoted NiAl mixed oxides shifts to lower value, and the surface Ni-O bond is weakened, thus the reduction peak of surface NiO moves to lower temperature, and the catalytic activity is improved.

Density functional studies on dinuclear {NiIIGdIII} and trinuclear {NiIIGdIIINiII} complexes: magnetic exchange and magneto-structural maps

Theoretical calculations using density functional methods have been performed on two dinuclear {Ni(II)-Gd(III)} and two trinuclear {Ni(II)-Gd(III)-Ni(II)} complexes having two and three μ-OR (R = alkyl or aromatic groups) bridging groups. The different magnetic behaviour, having moderately strong ferromagnetic coupling for complexes having two μ-OR groups and weak ferromagnetic coupling for complexes having three μ-OR groups, observed experimentally is very well reproduced by the calculations. Additionally, computation of overlap integrals MO and NBO analysis reveals a clear increase in antiferromagnetic contribution to the net exchange for three μ-OR bridged {Ni-Gd} dimers and also provides several important clues regarding the mechanism of magnetic coupling. Besides, MO and NBO analysis discloses the role of the empty 5d orbitals of the Gd(III) ion on the mechanism of magnetic coupling. Magneto-structural correlations for Ni-O-Gd bond angles, Ni-O and Gd-O bond distances, and the Ni-O-Gd-O dihedral angle have been developed and compared with the published experimental {Ni-Gd} structures and their J values indicate that the Ni-O-Gd bond angles play a prominent role in these types of complexes. The computation has then been extended to two trinuclear {Ni(II)-Gd(III)-Ni(II)} complexes and here both the {Ni-Gd} and the {Ni-Ni} interactions have been computed. Our calculations reveal that, for both structures studied, the two {NiGd} interactions are ferromagnetic and are similar in strength. The {Ni-Ni} interaction is antiferromagnetic in nature and our study reveals that its inclusion in fitting the magnetic data is necessary to obtain a reliable set of spin Hamiltonian parameters. Extensive magneto-structural correlations have been developed for the trinuclear complexes and the observed J trend for the trinuclear complex is similar to that of the dinuclear {Ni-Gd} complex. In addition to the structural parameters discussed above, for trinuclear complexes the twist angle between the two Ni-O-Gd planes is also an important parameter which influences the J values.

μ-2,3,5,6-Tetrakis(2-pyridyl)pyrazine-κ6N6,N1,N2:N3,N4,N5]bis[diaqua(dihydrogenm-phenylenediphosphonato-κO)nickel(II)] dihydrate

The title compound [Ni2(C6H6O6P2)2(C24H16N6)(H2O)4]·2H2O or [Ni2(tpyprz)(1,3-HO3PC6H4PO3H)2(H2O)4]·2H2O [tpyprz = tetra­kis­(2-pyrid­yl)pyrazine, C24H16N6] is a binuclear complex with a crystallographic inversion center located at the center of the pyrazine ring. The equivalent nickel(II) sites exhibit a distorted {NiO3N3} octa­hedral coordination, with the three nitro­gen donors of each terminus of the tpyprz ligand in a meridional orientation. An aqua ligand occupies the position trans to the pyrazine nitro­gen donor, while the second aqua ligand is trans to the oxygen donor of the dihydrogen-1,3-phenyl­diphospho­nate ligand. The Ni—O and Ni—N bond lengths fall in the range 2.011 (3) to 2.089 (3) Å. The protonation sites on the organo­phospho­nate ligand are evident in the significantly longer P—O bonds compared to the unprotonated sites. In the crystal structure, the complex mol­ecules and the solvent water mol­ecules are linked into a three-dimensional hydrogen-bonded framework through O—H⋯O inter­actions between the aqua ligands, the protonated organo­phospho­nate oxygen atoms and the water mol­ecules of crystallization. Intra­molecular π-stacking between the phenyl group of the phospho­nate ligand and a pyridyl group of the tpyprz ligand, at a distance of 3.244 (5) Å between ring centroids, is also observed.

Acetato(N-[(E)-1-(6-methyl-2-pyridyl)methylidene]-2-{2-[(E)-1-(6-methyl-2-pyridyl)methylideneamino]phenethyl}aniline)nickel(II) perchlorate

In the title complex, [Ni(CH3COO)(C28H26N4)]ClO4, the NiII atom is coordinated by two imine N atoms and two pyridine N atoms of the N-[(E)-1-(6-methyl-2-pyrid­yl)methyl­idene]-2-(2-[(E)-1-(6-methyl-2-pyrid­yl)methyl­idene­amino]­pheneth­yl)aniline donor ligand and two O atoms of the acetate ion in a distorted octa­hedral coordination. The average Ni—N and Ni—O bond lengths are 2.131 (13) and 2.098 (11) Å, respectively. An intramolecular N—H⋯O inter­action occurs. Relatively weak inter­molecular C—H⋯O inter­actions between the ligands and the ClO4 − ions result in a chain extending along the b axis.

Analysis of local structure of Ru1-xNixO2 electrocatalytic materials

Nanocrystalline Ru1-xNixO2 materials were synthesized by a solution method. Local structure around doped Ni atoms was characterized by extended X-ray absorption fine structure (EXAFS) functions obtained from X-ray absorption spectra acquired at Ni-K edge (8333eV). It was found that Ni ions are confined to the Ru site in the RuO2 rutile-type crystal structure, and Ni atoms tend to group by entering neighbouring sites along the body diagonal of rutile lattice. Such a neighbourhood of two Ni atoms may act as an active site for oxygen evolution by promoting simultaneous two electron transfer from the absorbed molecule of water. The refined Ni-O bond distances suggest that oxidation state of Ni ions is between +2 and +3.

Tetraaquabis(nicotinamide-κN1)cobalt(II) bis(2-fluorobenzoate)

The title complex, [Co(C6H6N2O)2(H2O)4](C7H4FO2)2, contains one Co(II) atom (site symmetry ), two monodentate nicotin­amide (NA) ligands, four coordinated water mol­ecules and two 2-fluoro­benzoate (FB) anions. The four O atoms in the equatorial plane around the Co atom form a slightly distorted square-planar arrangement, while the slightly distorted octa­hedral coordination is completed by the two N atoms of the NA ligands in the axial positions. The dihedral angle between the carboxyl group and the adjacent benzene ring is 29.8 (3)°, while the pyridine and benzene rings are oriented at a dihedral angle of 7.97 (12)°. In the crystal structure, mol­ecules are linked by O—H⋯O, N—H⋯O and N—H⋯F hydrogen bonds, forming an infinite three-dimensional network. π–π Contacts between the pyridine and benzene rings [centroid–centroid distance = 3.673 (3) Å] may further stabilize the crystal structure.

DFT-UX3LYP Studies on the Coordination Chemistry of Ni2+. Part 1: Six Coordinate [Ni(NH3)n(H2O)6−n]2+Complexes

DFT calculations with the UX3LYP hybrid functional and a medium-sized 6-311++G(d,p) basis set were performed to examine the gas-phase structure of paramagnetic (S = 1) six-coordinate complexes [Ni(NH3)n(H2O)(6-n)](2+), 0 < or = n < or = 6. Significant interligand hydrogen bonding was found in [Ni(H2O)6](2+), but this becomes much less significant as NH3 replaces H2O in the coordination sphere of the metal. Bond angles and bond lengths obtained from these calculations compare reasonably well with available crystallographic data. The mean calculated Ni-O bond length in [Ni(H2O)6](2+) is 2.093 A, which is 0.038 A longer than the mean of the crystallographically observed values (2.056(22) A, 108 structures) but within 2sigma of the experimental values. The mean calculated Ni-N bond length in [Ni(NH3)6](2+) is 2.205(3) A, also longer (by 0.070 A) than the crystallographically observed mean (2.135(18) A, 7 structures). Valence bond angles are reproduced within 1 degree. The successive replacement of H2O by NH3 as ligands results in an increase in the stabilization energy by 7 +/- 2 kcal mol(-1) per additional NH3 ligand. The experimentally observed increase in the lability of H2O in Ni(II) as NH3 replaces H2O in the coordination sphere is explained by an increase in the Ni-OH2 bond length. It was found from a natural population analysis that complexes with the highest stabilization energies are associated with the greatest extent of ligand-to-metal charge transfer, and the transferred electron density is largely accommodated in the metal 4s and 3d orbitals. An examination of the charge density rho bcp and the Laplacian of the charge density nabla(2)rho(bcp) at the metal-ligand bond critical points (bcp) in the series show a linear correlation with the charge transferred to the metal. Values of nabla(2)rho(bcp) are positive, indicative of a predominantly closed-shell interaction. The charge transferred to the metal increases as n, the number of NH3 ligands in the complex, increases. This lowers the polarizing ability of the metal on the ligand donors and the average metal-ligand bond length increases, resulting in a direct correlation between the dissociation energy of the complexes and the reciprocal of the average metal-ligand bond length. There is a strong correlation between the charge transferred to the metal and experimental DeltaH values for successive replacement of H2O by NH3, but a correlation with stability constants (log beta values) breaks when n = 5 and 6, probably because of entropic effects in solution. Nevertheless, DFT calculations may be a useful way of estimating the stability constants of metal-ligand systems.

Molecular dynamics simulation study of nanoscale passive oxide growth on Ni-Al alloy surfaces at low temperatures

Oxidation kinetics of Ni-Al (100) alloy surface is investigated at low temperatures (300--600 K) and at different gas pressures using molecular dynamics (MD) simulations with dynamic charge transfer between atoms. Monte Carlo simulations employing the bond order simulation model are used to generate the surface segregated minimum energy initial alloy configurations for use in the MD simulations. In the simulated temperature-pressure-composition regime for Ni-Al alloys, we find that the oxide growth curves follow a logarithmic law beyond an initial transient regime. The oxidation rates for Ni-Al alloys were found to decrease with increasing Ni composition. Structure and dynamical correlations in the metal/oxide/gas environments are used to gain insights into the evolution and morphology of the growing oxide film. Oxidation of Ni-Al alloys is characterized by the absence of Ni-O bond formation. Oxide films formed on the various simulated metal surfaces are amorphous in nature and have a limiting thickness ranging from $\ensuremath{\sim}1.7\text{ }\text{nm}$ for pure Al to 1.1 nm for 15% Ni-Al surfaces. Oxide scale analysis indicates significant charge transfer as well as variation in the morphology and structure of the oxide film formed on pure Al and 5% Ni-Al alloy. For oxide scales thicker than 1 nm, the oxide structure in case of pure Al exhibits a mixed tetrahedral $({\text{AlO}}_{4}\ensuremath{\sim}37%)$ and octahedral $({\text{AlO}}_{6}\ensuremath{\sim}19%)$ environment, whereas the oxide scale on Ni-Al alloy surface is almost entirely composed of tetrahedral environment $({\text{AlO}}_{4}\ensuremath{\sim}60%)$ with very little ${\text{AlO}}_{6}$ $(l1%)$. The oxide growth kinetic curves are fitted to Arrhenius-type plots to get an estimate of the activation energy barriers for metal oxidation. The activation energy barrier for oxidation on pure Al was found to be 0.3 eV lower than that on 5% Ni-Al surface. Atomistic observations as well as calculated dynamical correlation functions indicate a layer by layer growth on pure Al, whereas a transition from an initial island growth mode $(l75\text{ }\text{ps})$ to a layer by layer mode $(g100\text{ }\text{ps})$ occurs in case of 5% Ni-Al alloy. The oxide growth on both pure Al and Ni-Al alloy surfaces occurs by inward anion and outward cation diffusions. The cation diffusion in both the cases is similar, whereas the anion diffusion in case of 5% Ni-Al is 25% lower than pure Al, thereby resulting in reduced self-limiting thickness of oxide scale on the alloy surface. The simulation findings agree well with previously reported experimental observations of oxidation on Ni-Al alloy surface.