Density Functional Theory Calculations on the Complexation of p-Arsanilic Acid with Hydrated Iron Oxide Clusters: Structures, Reaction Energies, and Transition States

AbstractThe functionalisation of C60 fullerene with 2,3-dimethylene-1,4-dioxane (I) and 2,5-dioxabicyclo [4.2.0]octa-1(8),6-diene (II) was investigated by the use of density functional theory calculations in terms of its energetic, structural, field emission, and electronic properties. The functionalisation of C60 with I was previously reported experimentally. The I and II molecules are preferentially attached to a C—C bond shared and located between two hexagons of C60 via [4+2] and [2+2] cycloadditions bearing reaction energies of −15.9 kcal mol−1 and −72.4 kcal mol−1, respectively. The HOMO-LUMO energy gap and work function of C60 are significantly reduced following completion of the reactions. The field electron emission current of the C60 surface will increase after functionalisation of either the I or II molecule.

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A density functional theory study on the mechanism of the allylpalladium-catalyzed dehydrogenation of aldehydes and cyclic ketones

Progress in Reaction Kinetics and Mechanism ◽

10.1177/14686783211020600 ◽

2021 ◽

Vol 46 ◽

pp. 146867832110206

Author(s):

Anan Haj Ichia Arisha

Keyword(s):

Density Functional Theory ◽

Gas Phase ◽

Density Functional ◽

Transition States ◽

Density Functional Theory Calculations ◽

Carbonyl Complex ◽

Cyclic Ketones ◽

Complex Catalyst ◽

Functional Theory ◽

Hydride Elimination

The results of density functional theory calculations at the APFD/SDD level are detailed herein in order to study the main steps in the α,β-dehydrogenation of aldehydes and cyclic ketones in the presence of an allylpalladium complex catalyst. The mechanism is believed to proceed via an allylpalladium enolate complex (A) in equilibrium with the carbon-bonded complex (B), followed by β-hydride elimination to yield the allylpalladium hydride coordinated to the α,β-unsaturated carbonyl (complex C). The optimized structures and detailed energy profiles of these intermediates and their corresponding transition states are presented herein. The results indicate that the intermediates and their transition states are more stable in THF solution than in the gas phase. In detail, the energy barriers for the two steps are found to be 25.22 and 11.13 kcal/mol, respectively, in THF, and 29.93 and 9.77 kcal/mol, respectively, in the gas phase.

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Iron oxide cluster induced barrier-free conversion of nitric oxide to ammonia

Chemical Communications ◽

10.1039/c4cc09467k ◽

2015 ◽

Vol 51 (19) ◽

pp. 4062-4064 ◽

Cited By ~ 6

Author(s):

Keisuke Takahashi

Keyword(s):

Nitric Oxide ◽

Density Functional Theory ◽

Iron Oxide ◽

Nitrogen Oxide ◽

Density Functional ◽

Density Functional Theory Calculations ◽

Oxide Cluster ◽

Functional Theory ◽

No Conversion ◽

Barrier Free

Nitrogen oxide (NO) conversion to ammonia (NH3) over iron oxide clusters is investigated using density functional theory calculations.

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Structures and reaction rates of the gaseous oxidation of SO2 by an O3−(H2O)0-5 cluster – a density functional theory investigation

Atmospheric Chemistry and Physics ◽

10.5194/acp-12-3639-2012 ◽

2012 ◽

Vol 12 (8) ◽

pp. 3639-3652 ◽

Cited By ~ 23

Author(s):

N. Bork ◽

T. Kurtén ◽

M. B. Enghoff ◽

J. O. P. Pedersen ◽

K. V. Mikkelsen ◽

...

Keyword(s):

Density Functional Theory ◽

Atmospheric Chemistry ◽

Density Functional ◽

Transition States ◽

Density Functional Theory Calculations ◽

Reaction Rates ◽

Water Molecules ◽

Functional Theory ◽

High Entropy ◽

Collision Complexes

Abstract. Based on density functional theory calculations we present a study of the gaseous oxidation of SO2 to SO3 by an anionic O3−(H2O)n cluster, n = 0–5. The configurations of the most relevant reactants, transition states, and products are discussed and compared to previous findings. Two different classes of transition states have been identified. One class is characterised by strong networks of hydrogen bonds, very similar to the reactant complexes. The other class is characterised by sparser structures of hydration water and is stabilised by high entropy. At temperatures relevant for atmospheric chemistry, the most energetically favourable class of transition states vary with the number of water molecules attached. A kinetic model is utilised, taking into account the most likely outcomes of the initial SO2 O3−(H2O)n collision complexes. This model shows that the reaction takes place at collision rates regardless of the number of water molecules involved. A lifetime analysis of the collision complexes supports this conclusion. Hereafter, the thermodynamics of water and O2 condensation and evaporation from the product SO3−O2(H2O)n cluster is considered and the final products are predicted to be O2SO3− and O2SO3−(H2O)1. The low degree of hydration is rationalised through a charge analysis of the relevant complexes. Finally, the thermodynamics of a few relevant reactions of the O2SO3− and O2SO3−(H2O)1 complexes are considered.

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