Experimental and theoretical study of monoligand complexes of nickel atoms with simple alkynes

Monoligand complexes of nickel atoms with simple alkynes have been investigated by kinetic studies of association reactions of nickel atoms with ethyne, propyne, and 2-butyne in the gas phase near room temperature, and by quantum chemical calculations on the Ni[C2H2] complex using a Linear Combination of Gaussian-Type Orbitals – Density Functional (LCGTO–DF) method. Experimental estimates of binding energies of the monoligand complexes have been made by using RRKM unimolecular reaction theory to model the pressure dependence of second-order rate coefficients for the association reactions: [Formula: see text] and 29 ± 5 kcal mol−1, for Ni[C2H2], Ni[propyne], and Ni[2-butyne], respectively. The trend in binding energy with methyl substitution on ethyne is discussed and compared with similar data for monoligand complexes of alkynes with copper atoms. The harmonic vibrational frequencies and binding energy for the 1A1 ground state of Ni[C2H2] have been calculated using the LCGTO–DF method, and the results are compared with experimental data on the infrared spectrum of matrix-isolated Ni[C2H2] and with the estimate of the binding energy of Ni[C2H2] from the present experimental study. There is excellent agreement between the experimental and theoretical results. The calculations indicate that at least one triplet state of Ni[C2H2] is bound relative to ground state Ni + C2H2 reactants. This is consistent with indications from the kinetic results that the association reaction occurs on more than one potential energy surface.

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A DFT study of spherands containing five anisyl groups — Highly preorganized to bind the alkali metal

Canadian Journal of Chemistry ◽

10.1139/v06-130 ◽

2006 ◽

Vol 84 (8) ◽

pp. 1045-1049 ◽

Cited By ~ 4

Author(s):

Shabaan AK Elroby ◽

Kyu Hwan Lee ◽

Seung Joo Cho ◽

Alan Hinchliffe

Keyword(s):

Density Functional Theory ◽

Binding Energy ◽

Density Functional ◽

Ionic Radius ◽

Binding Energies ◽

Cavity Size ◽

X Ray Diffraction ◽

Functional Theory ◽

X Ray ◽

Good Agreement

Although anisyl units are basically poor ligands for metal ions, the rigid placements of their oxygens during synthesis rather than during complexation are undoubtedly responsible for the enhanced binding and selectivity of the spherand. We used standard B3LYP/6-31G** (5d) density functional theory (DFT) to investigate the complexation between spherands containing five anisyl groups, with CH2–O–CH2 (2) and CH2–S–CH2 (3) units in an 18-membered macrocyclic ring, and the cationic guests (Li+, Na+, and K+). Our geometric structure results for spherands 1, 2, and 3 are in good agreement with the previously reported X-ray diffraction data. The absolute values of the binding energy of all the spherands are inversely proportional to the ionic radius of the guests. The results, taken as a whole, show that replacement of one anisyl group by CH2–O–CH2 (2) and CH2–S–CH2 (3) makes the cavity bigger and less preorganized. In addition, both the binding and specificity decrease for small ions. The spherands 2 and 3 appear beautifully preorganized to bind all guests, so it is not surprising that their binding energies are close to the parent spherand 1. Interestingly, there is a clear linear relation between the radius of the cavity and the binding energy (R2 = 0.999).Key words: spherands, preorganization, density functional theory, binding energy, cavity size.

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Theoretical insight on the treatment of β-hexachlorocyclohexane waste through alkaline dehydrochlorination

Scientific Reports ◽

10.1038/s41598-021-88060-7 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Alicia Bescós ◽

Clara I. Herrerías ◽

Zoel Hormigón ◽

José Antonio Mayoral ◽

Luis Salvatella

Keyword(s):

Density Functional ◽

Kinetic Studies ◽

Alkaline Treatment ◽

Functional Study ◽

Reaction Intermediates ◽

Preferential Formation ◽

Reaction Intermediate ◽

Rate Determining Step ◽

Dehydrochlorination Reaction ◽

Theoretical Results

AbstractThe occurrence of 4.8–7.2 million tons of hexachlorocyclohexane (HCH) isomers stocked in dumpsites around the world constitutes a huge environmental and economical challenge because of their toxicity and persistence. Alkaline treatment of an HCH mixture in a dehydrochlorination reaction is hampered by the low reactivity of the β-HCH isomer (HCl elimination unavoidably occurring through syn H–C–C–Cl arrangements). More intriguingly, the preferential formation of 1,2,4-trichlorobenzene in the β-HCH dehydrochlorination reaction (despite the larger thermodynamical stability of the 1,3,5-isomer) has remained unexplained up to now, though several kinetic studies had been reported. In this paper, we firstly show a detailed Density Functional study on all paths for the hydroxide anion-induced elimination of β-HCH through a three-stage reaction mechanism (involving two types of reaction intermediates). We have now demonstrated that the first reaction intermediate can follow several alternative paths, the preferred route involving abstraction of the most acidic allylic hydrogen which leads to a second reaction intermediate yielding only 1,2,4-trichlorobenzene as the final reaction product. Our theoretical results allow explaining the available experimental data on the β-HCH dehydrochlorination reaction (rate-determining step, regioselectivity, instability of some reaction intermediates).

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The binding energies of atomic nuclei III. Nuclear forces and the ground state of oxygen 16

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1959.0187 ◽

1959 ◽

Vol 253 (1273) ◽

pp. 186-198 ◽

Cited By ~ 12

Keyword(s):

Binding Energy ◽

Electron Scattering ◽

Ground State ◽

Binding Energies ◽

Wave Functions ◽

Unperturbed System ◽

Core Radius ◽

Nuclear Forces ◽

Potential Core ◽

Atomic Nuclei

The r. m. s. radius and the binding energy of oxygen 16 are calculated for several different internueleon potentials. These potentials all fit the low-energy data for two nucleons, they have hard cores of differing radii, and they include the Gammel-Thaler potential (core radius 0·4 fermi). The calculated r. m. s. radii range from 1·5 f for a potential with core radius 0·2 f to 2·0 f for a core radius 0·6 f. The value obtained from electron scattering experiments is 2·65 f. The calculated binding energies range from 256 MeV for a core radius 0·2 f to 118 MeV for core 0·5 f. The experimental value of binding energy is 127·3 MeV. The 25% discrepancy in the calculated r. m. s. radius may be due to the limitations of harmonic oscillator wave functions used in the unperturbed system.

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Spin-polarized hydrogen, deuterium, and tritium: I. Ground-state energy calculated by a lowest order constrained-variation method

Canadian Journal of Physics ◽

10.1139/p89-008 ◽

1989 ◽

Vol 67 (1) ◽

pp. 63-71 ◽

Cited By ~ 2

Author(s):

Magne Haugen ◽

Erlend Østgaard

Keyword(s):

Binding Energy ◽

Molar Volume ◽

Ground State ◽

Particle Density ◽

Variation Method ◽

Ground State Binding Energy ◽

Spin Polarized ◽

Hydrogen Deuterium ◽

Constrained Variation ◽

Theoretical Results

The ground-state energy of spin-polarized hydrogen, deuterium, and tritium is calculated by means of a modified variational lowest order constrained-variation method, and the calculations are done for five different two-body potentials. Spin-polarized H↓ is not self-bound according to our theoretical results for the ground-state binding energy. For spin-polarized D↓, however, we obtain theoretical results for the ground-state binding energy per particle from −0.42 K at an equilibrium particle density of 0.25 σ−3 or a molar volume of 121 cm3/mol to + 0.32 K at an equilibrium particle density of 0.21 σ−3 or a molar volume of 142 cm3/mol, where σ = 3.69 Å (1 Å = 10−10 m). It is, therefore, not clear whether spin-polarized deuterium should be self-bound or not. For spin-polarized T↓, we obtain theoretical results for the ground-state binding energy per particle from −4.73 K at an equilibrium particle density of 0.41 σ−3 or a molar volume of 74 cm3/mol to −1.21 K at an equilibrium particle density of 0.28 σ−3 or a molar volume of 109 cm3/mol.

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Binding Energies of Organic Charge-Transfer Complexes Calculated by First-Principles Methods

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19981223 ◽

1998 ◽

Vol 63 (8) ◽

pp. 1223-1244 ◽

Cited By ~ 8

Author(s):

Cordula Rauwolf ◽

Achim Mehlhorn ◽

Jürgen Fabian

Keyword(s):

Density Functional Theory ◽

Charge Transfer ◽

Ground State ◽

Density Functional ◽

Binding Energies ◽

Basis Set ◽

Dispersion Energy ◽

Functional Theory ◽

Basis Set Superposition Error ◽

Donor And Acceptor

Weak interactions between organic donor and acceptor molecules resulting in cofacially-stacked aggregates ("CT complexes") were studied by second-order many-body perturbation theory (MP2) and by gradient-corrected hybrid Hartree-Fock/density functional theory (B3LYP exchange-correlation functional). The complexes consist of tetrathiafulvalene (TTF) and related compounds and tetracyanoethylene (TCNE). Density functional theory (DFT) and MP2 molecular equilibrium geometries of the component structures are calculated by means of 6-31G*, 6-31G*(0.25), 6-31++G**, 6-31++G(3df,2p) and 6-311G** basis sets. Reliable molecular geometries are obtained for the donor and acceptor compounds considered. The geometries of the compounds were kept frozen in optimizing aggregate structures with respect to the intermolecular distance. The basis set superposition error (BSSE) was considered (counterpoise correction). According to the DFT and MP2 calculations laterally-displaced stacks are more stable than vertical stacks. The charge transfer from the donor to the acceptor is small in the ground state of the isolated complexes. The cp-corrected binding energies of TTF/TCNE amount to -1.7 and -6.3 kcal/mol at the DFT(B3LYP) and MP2(frozen) level of theory, respectively (6-31G* basis set). Larger binding energies were obtained by Hobza's 6-31G*(0.25) basis set. The larger MP2 binding energies suggest that the dispersion energy is underestimated or not considered by the B3LYP functional. The energy increases when S in TTF/TCNE is replaced by O or NH but decreases with substitution by Se. The charge-transferred complexes in the triplet state are favored in the vertical arrangement. Self-consistent-reaction-field (SCRF) calculations predicted a gain in binding energy with solvation for the ground-state complex. The ground-state charge transfer between the components is increased up to 0.8 e in polar solvents.

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The binding energies of the hydrogen isotopes

Mathematical Proceedings of the Cambridge Philosophical Society ◽

10.1017/s0305004100020302 ◽

1938 ◽

Vol 34 (3) ◽

pp. 365-374 ◽

Cited By ~ 14

Author(s):

A. H. Wilson

Keyword(s):

Wave Equation ◽

Binding Energy ◽

Potential Energy ◽

Ground State ◽

Hydrogen Isotope ◽

Hydrogen Isotopes ◽

Binding Energies ◽

Variation Method

The wave equation for the deuteron in its ground state is solved on the assumption that the mutual potential energy of a neutron and a proton is of the form r−1e−λr. The binding energy of the hydrogen isotope H3 is calculated approximately by the variation method.

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Non-relativistic s-wave binding energies of Λ-particle in hypernuclei

Modern Physics Letters A ◽

10.1142/s021773231650084x ◽

2016 ◽

Vol 31 (14) ◽

pp. 1650084 ◽

Cited By ~ 1

Author(s):

A. Armat ◽

H. Hassanabadi

Keyword(s):

Experimental Data ◽

Binding Energy ◽

Analytical Solution ◽

Schrödinger Equation ◽

Ground State ◽

Schrodinger Equation ◽

Binding Energies ◽

S Wave ◽

Ground State Binding Energy ◽

Type Interaction

In this work, the ground state binding energy of [Formula: see text]-particle in hypernuclei is investigated by using analytical solution of non-relativistic Schrödinger equation in the presence of a generalized Woods–Saxon-type interaction. The comparison with the experimental data is motivating.

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The investigation of 2D monolayers as potential chelation agents in Alzheimer’s disease

10.7287/peerj.preprints.27942v3 ◽

2019 ◽

Author(s):

Neha Pavuluru ◽

Xuan Luo

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Charge Transfer ◽

Binding Energy ◽

Amyloid Beta ◽

Density Functional ◽

Density Functional Theory Calculations ◽

Binding Energies ◽

Amyloid Beta Protein ◽

Functional Theory

In this study, we conducted Density Functional Theory calculations comparing the binding energy of the copper- Amyloid-beta complex to the binding energies of potential chelation materials. We used the first-coordination sphere of the truncated high-pH Amyloid-beta protein subject to computational limits. Binding energy and charge transfer calculations were evaluated for copper’s interaction with potential chelators: monolayer boron nitride, monolayer molybdenum disulfide, and monolayer silicene. Silicene produced the highest binding energies to copper, and the evidence of charge transfer between copper and the monolayer proves that there is a strong ionic bond present. Although our three monolayers did not directly present chelation potential, the absolute differences between the binding energies of the silicene binding sites and the Amyloid-beta binding site were minimal proving that further research in silicene chelators may be useful for therapy in Alzheimer’s disease.

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Antimony Selenide Crystals Encapsulated within Single Walled Carbon Nanotubes-A DFT Study

E-Journal of Chemistry ◽

10.1155/2009/837807 ◽

2009 ◽

Vol 6 (s1) ◽

pp. S147-S152 ◽

Cited By ~ 5

Author(s):

Navaratnarajah Kuganathan

Keyword(s):

Carbon Nanotubes ◽

Binding Energy ◽

Density Functional ◽

Density Functional Theory Calculations ◽

Single Walled Carbon Nanotubes ◽

Binding Energies ◽

Single Walled Carbon ◽

Transmission Electron ◽

Antimony Selenide ◽

Walled Carbon Nanotubes

The structure and binding energies of antimony selenide crystals encapsulated within single-walled carbon nanotubes are studied using density functional theory. Calculations were performed on the simulated Sb2Se3structure encapsulated within single walled nanotube to investigate the perturbations on the Sb2Se3crystal and tube structure and electronic structure and to estimate the binding energy. The calculated structures are in good agreement with the experimental high resolution transmission electron microscopy images of the Sb2Se3@SWNT. The calculated binding energy shows that larger diameter tube could accommodate the Sb2Se3crystals exothermically. Minimal charge transfer is observed between nanotube and the Sb2Se3crystals.

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