Density Functional Theory and Perturbation Calculations on Some Lewis Acid−Base Complexes. A Systematic Study of Substitution Effects

1996 ◽  
Vol 100 (37) ◽  
pp. 15079-15082 ◽  
Author(s):  
Anne Skancke ◽  
P. N. Skancke
Keyword(s):  
Density Functional Theory ◽  
Lewis Acid ◽  
Systematic Study ◽  
Density Functional ◽  
Substitution Effects ◽  
Acid Base ◽  
Functional Theory

A Comparison of the Lewis Basicity of Diamidocarbenes and Diaminocarbenes

2015 ◽  
Vol 68 (7) ◽  
pp. 1084 ◽  
Author(s):  
Chin-Hung Lai
Keyword(s):  
Density Functional Theory ◽  
Lewis Acid ◽  
Base Pair ◽  
Bond Energy ◽  
Density Functional ◽  
Hydrogen Abstraction ◽  
Density Functional Theory Calculations ◽  
Acid Base ◽  
Functional Theory ◽  
The Density Functional Theory

In this study, density functional theory calculations, using the M06-2X functional, were performed to investigate the efficiencies of various carbenes in inducing hydrogen abstraction in BH3 through the formation of a Lewis acid–base pair with BH3. The density functional theory results indicate that diamidocarbenes are more efficient in reducing the B–H bond energy of BH3 than diaminocarbenes. Natural bond orbital and combined charge and bond energy analyses were performed to investigate the Lewis acid–base pair formed by BH3 and the title carbenes.

scholarly journals The Phospha-Bora-Wittig Reaction

2021 ◽  
Author(s):  
Andryj Borys ◽  
Ella Rice ◽  
Gary Nichol ◽  
Michael Cowley
Keyword(s):  
Density Functional Theory ◽  
Lewis Acid ◽  
Carbonyl Compounds ◽  
Density Functional ◽  
Wittig Reaction ◽  
Acid Base ◽  
Functional Theory ◽  
Direct Preparation ◽  
Wittig Reactions

Here, we report the phospha-bora-Wittig reaction for the direct preparation of phosphaalkenes from aldehydes, ketones, esters, or amides. The transient phosphaborene Mes*P=B-NR2 reacts with carbonyl compounds to form 1,2,3-phosphaboraoxetanes, analogues of oxaphosphetane intermediates in the classical Wittig reaction. 1,2,3-phosphaboraoxetanes undergo thermal or Lewis acid/base-promoted cycloreversion, yielding phosphaalkenes. Experimental and density functional theory studies reveal far-reaching similarities between classical and phospha-bora-Wittig reactions.

scholarly journals The Phospha-Bora-Wittig Reaction

2021 ◽  
Author(s):  
Andryj Borys ◽  
Ella Rice ◽  
Gary Nichol ◽  
Michael Cowley
Keyword(s):  
Density Functional Theory ◽  
Lewis Acid ◽  
Carbonyl Compounds ◽  
Density Functional ◽  
Wittig Reaction ◽  
Acid Base ◽  
Functional Theory ◽  
Direct Preparation ◽  
Wittig Reactions

Here, we report the phospha-bora-Wittig reaction for the direct preparation of phosphaalkenes from aldehydes, ketones, esters, or amides. The transient phosphaborene Mes*P=B-NR2 reacts with carbonyl compounds to form 1,2,3-phosphaboraoxetanes, analogues of oxaphosphetane intermediates in the classical Wittig reaction. 1,2,3-phosphaboraoxetanes undergo thermal or Lewis acid/base-promoted cycloreversion, yielding phosphaalkenes. Experimental and density functional theory studies reveal far-reaching similarities between classical and phospha-bora-Wittig reactions.

Catalysis of the Quadricyclane to Norbornadiene Rearrangement by SnCl2 and CuSO4

2010 ◽  
Vol 65 (3) ◽  
pp. 347-r369 ◽  
Author(s):  
Tatyana E Shubina ◽  
Timothy Clark
Keyword(s):  
Density Functional Theory ◽  
Electron Transfer ◽  
Dft Calculations ◽  
Lewis Acid ◽  
Density Functional ◽  
Acid Base ◽  
Functional Theory ◽  
Catalysed Reaction ◽  
Base Process ◽  
Molecular Catalysts

Ab initio and density-functional theory (DFT) calculations have been used to investigate the model rearrangements of quadricyclane to norbornadiene catalysed by single CuSO4 and SnCl2 molecules. The isolated reactions with the two molecular catalysts proceed via electron-transfer catalysis in which the hydrocarbon is oxidised, in contrast to systems investigated previously in which the substrate was reduced. The even-electron SnCl2-catalysed reaction shows singlet-triplet two-state reactivity. Solvation by a single methanol molecule changes the mechanism of the rearrangement to a classical Lewis acid-base process.

The structure and activity of potassium supported on SBA-15 molecular sieve: Density functional theory study

2014 ◽  
Vol 13 (01) ◽  
pp. 1350076 ◽  
Author(s):  
Bing Liu ◽  
Daxi Wang ◽  
Zhongxue Wang ◽  
Zhen Zhao ◽  
Yu Chen ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Lewis Acid ◽  
Molecular Sieve ◽  
Active Sites ◽  
Density Functional ◽  
Structural Model ◽  
Vibrational Frequencies ◽  
Oxygen Molecule ◽  
Lewis Base ◽  
Functional Theory

The geometries, vibrational frequencies, electronic properties and reactivity of potassium supported on SBA-15 have been theoretically investigated by the density functional theory (DFT) method. The structural model of the potassium supported on SBA-15 was constructed based on our previous work [Wang ZX, Wang DX, Zhao Z, Chen Y, Lan J, A DFT study of the structural units in SBA-15 mesoporous molecular sieve, Comput. Theor. Chem.963, 403, 2011]. This paper is the extension of our previous work. The most favored location of potassium atom was obtained by the calculation of substitution energy. The calculated vibrational frequencies of K /SBA-15 are in good agreement with the experimental results. By analyzing the properties of electronic structure, we found that the O atom of Si - O (2)- K group acts as the Lewis base center and the K atom acts as the Lewis acid center. The reactivity of K /SBA-15 was investigated by calculating the activation of oxygen molecule. The oxygen molecule can be activated by K /SBA-15 with an energy barrier of 103.2 kJ/mol. In the final state, the activated oxygen atoms become new Lewis acid centers, which are predicted to act as the active sites in the catalytic reactions. This study provides a deep insight into the properties of supported potassium catalysts and offers fundamental information for further research.

scholarly journals Substitution Effects on the Optoelectronic Properties of Coumarin Derivatives

2019 ◽  
Vol 10 (1) ◽  
pp. 144
Author(s):  
Amit Kumar ◽  
Roberto Baccoli ◽  
Antonella Fais ◽  
Alberto Cincotti ◽  
Luca Pilia ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Binding Energy ◽  
Molecular Orbital ◽  
Density Functional ◽  
Optoelectronic Properties ◽  
Exciton Binding Energy ◽  
Basis Set ◽  
Substitution Effects ◽  
Coumarin Derivatives ◽  
Functional Theory

Coumarin derivatives have gathered major attention largely due to their versatile utility in a wide range of applications. In this framework, we report a comparative computational investigation on the optoelectronic properties of 3-phenylcoumarin and 3-heteroarylcoumarin derivatives established as enzyme inhibitors. Specifically, we concentrate on the variation in the optoelectronic characteristics for the hydroxyl group substitutions within the coumarin moiety. In order to realize our aims, all-electron density functional theory and time dependent density functional theory calculations were performed with a localized Gaussian basis-set matched with a hybrid exchange–correlation functionals. Molecular properties such as highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energies, vertical ionization (IEV) and electron affinity energies, absorption spectra, quasi-particle gap, and exciton binding energy values are examined. Furthermore, the influence of solvent on the optical properties of the molecules is considered. We found a good agreement between the experimental (8.72 eV) and calculated (8.71 eV) IEV energy values for coumarin. The computed exciton binding energy of the investigated molecules indicated their potential optoelectronics application.

scholarly journals A systematic study on Pt based, subnanometer-sized alloy cluster catalysts for alkane dehydrogenation: effects of intermetallic interaction

2016 ◽  
Vol 18 (16) ◽  
pp. 10906-10917 ◽  
Author(s):  
Andreas W. Hauser ◽  
Paul R. Horn ◽  
Martin Head-Gordon ◽  
Alexis T. Bell
Keyword(s):  
Density Functional Theory ◽  
Systematic Study ◽  
Density Functional ◽  
Bimetallic Nanoparticles ◽  
Cluster Models ◽  
Functional Theory ◽  
Alkane Dehydrogenation ◽  
Alloy Cluster

The dehydrogenation of propane over platinum-based bimetallic nanoparticles is analyzed by the application of density functional theory to a series of tetrahedral Pt3X cluster models.

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