scholarly journals Theoretical Insight into the Reaction Mechanism and Kinetics for the Criegee Intermediate of anti-PhCHOO with SO2

Molecules ◽  
2020 ◽  
Vol 25 (13) ◽  
pp. 3041
Author(s):  
Benni Du ◽  
Weichao Zhang
Keyword(s):  
Reaction Mechanism ◽  
Potential Energy Surfaces ◽  
Density Functional ◽  
Reaction Pathways ◽  
Dissociation Pathway ◽  
Detailed Reaction Mechanism ◽  
Reaction Channels ◽  
Direct Dissociation ◽  
Energy Surfaces ◽  
Insight Into

In this study, the density functional theory (DFT) and CCSD(T) method have been performed to gain insight into the possible products and detailed reaction mechanism of the Criegee intermediate (CI) of anti-PhCHOO with SO2 for the first time. The potential energy surfaces (PESs) have been depicted at the UCCSD(T)/6-311++G(d,p)//UB3LYP/6-311++G(d,p) levels of theory with ZPE correction. Two different five-membered ring adducts, viz., endo PhCHOOS(O)O (IM1) and exo PhCHOOS(O)O (IM2) have been found in the entrance of reaction channels. Both direct and indirect reaction pathways from IM1 and IM2 have been considered for the title reaction. Our calculations show that the formation of PhCHO+SO3 (P1) via indirect reaction pathways from IM1 is predominant in all the pathways, and the production of P1 via direct dissociation pathway of IM1 and indirect reaction pathways of IM2 cannot be neglected. Moreover, PhCOOH+SO2 (P2) initiated from IM2 is identified as the minor product. According to the kinetic calculation, the total rate constant for the anti-PhCHOO+SO2 reaction is estimated to be 6.98 × 10−10 cm3·molecule−1·s−1 at 298 K.

Quantum Simulations of Preferable H2O Dissociation Pathway on the Ru-Alloyed Pt(111) Surface Based on Density Functional Theory

2020 ◽  
Vol 840 ◽  
pp. 495-500
Author(s):  
Victor Reynaldi ◽  
Wahyu Tri Cahyanto ◽  
Farzand Abdullatif
Keyword(s):  
Activation Energy ◽  
Density Functional Theory ◽  
Potential Energy Surfaces ◽  
Density Functional ◽  
Reaction Pathways ◽  
Dissociation Pathway ◽  
Reaction Route ◽  
Functional Theory ◽  
Energy Surfaces ◽  
Pes Scan

Reaction pathways for a water molecule dissociation (H2Oads) to form hydroxyl (OHads) and hydrogen (Hads) on the Ru-alloyed Pt(111) surface were computationally modelled on the basis of density functional theory (DFT). The aim of this study was to evaluate whether or not such a reaction can take place and to determine the most probable route for this reaction. To get the answer, we calculated the potential energy surfaces (PES) of the proposed reaction pathways. From the results of the PES scan, we then obtained the most preferential pathway for H2O dissociation, i.e., the reaction route with an activation energy of 0.72 eV. This activation energy value is lower than the value of pure Pt (111), the surface at which H2O dissociation can occur in the real system. Thus, it can be said that water splitting may be easier when catalyzing Ru-alloyed surfaces compared to pure Pt catalysts.

scholarly journals Three-component reaction involving isoquinoline and dimethyl acethylenedicarboxylate in the presence of indole: Theoretical and experimental investigations of the reaction mechanism

2021 ◽  
Vol 46 ◽  
pp. 146867832095686
Author(s):  
Mohammad Zakarianezhad ◽  
Sayyed Mostafa Habibi-Khorassani ◽  
Batoul Makiabadi ◽  
Elham Zeydabadi
Keyword(s):  
Reaction Mechanism ◽  
Potential Energy Surfaces ◽  
Reaction Rate ◽  
Product Configuration ◽  
Experimental Investigations ◽  
Uv Spectrophotometry ◽  
Three Component Reaction ◽  
Energy Surfaces ◽  
Theoretical Results ◽  
Reaction Rate Equation

The reaction kinetics among isoquinoline, dimethyl acetylenedicarboxylate, and indole (as NH-acid) were investigated using ultraviolet (UV) spectrophotometry. The reaction rate equation was obtained, the dependence of the reaction rate on different reactants was determined, and the overall rate constant ( kov) was calculated. By studying the effects of solvent, temperature, and concentration on the reaction rate, some useful information was obtained. A logical mechanism consistent with the experimental observations was proposed. Also, comprehensive theoretical studies were performed to evaluate the potential energy surfaces of all structures that participated in the reaction mechanism. Finally, the proposed mechanism was confirmed by the obtained results and the probable and logical reaction paths and also a correct product configuration were suggested based on the theoretical results.

scholarly journals The ANI-1ccx and ANI-1x Data Sets, Coupled-Cluster and Density Functional Theory Properties for Molecules

2020 ◽  
Author(s):  
Justin S. Smith ◽  
Roman Zubatyuk ◽  
Benjamin T. Nebgen ◽  
Nicholas Lubbers ◽  
Kipton Barros ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Potential Energy Surfaces ◽  
Density Functional ◽  
Atomic Charge ◽  
Density Functional Theory Calculations ◽  
Coupled Cluster ◽  
Data Sets ◽  
Data Set ◽  
Functional Theory ◽  
Energy Surfaces

<p>Maximum diversification of data is a central theme in building generalized and accurate machine learning (ML) models. In chemistry, ML has been used to develop models for predicting molecular properties, for example quantum mechanics (QM) calculated potential energy surfaces and atomic charge models. The ANI-1x and ANI-1ccx ML-based eneral-purpose potentials for organic molecules were developed through active learning; an automated data diversification process. Here, we describe the ANI-1x and ANI-1ccx data sets. To demonstrate data set diversity, we visualize them with a dimensionality reduction scheme, and contrast against existing data sets. The ANI-1x data set contains multiple QM properties from 5M density functional theory calculations, while the ANI-1ccx data set contains 500k data points obtained with an accurate CCSD(T)/CBS extrapolation. Approximately 14 million CPU core-hours were expended to generate this data. Multiple QM properties from density functional theory and coupled cluster are provided: energies, atomic forces, multipole moments, atomic charges, and more. We provide this data to the community to aid research and development of ML models for chemistry.</p>

scholarly journals Migration of Zeolite-Encapsulated Pt and Au Under Reducing Atmospheres

2021 ◽  
Author(s):  
Dianwei Hou ◽  
Christopher Heard
Keyword(s):  
Monte Carlo ◽  
Potential Energy Surfaces ◽  
Density Functional ◽  
Noble Metals ◽  
Kinetic Monte Carlo ◽  
Pore System ◽  
Kinetic Monte Carlo Simulations ◽  
Zeolite Lta ◽  
Metal Migration ◽  
Energy Surfaces

Unbiased density functional global optimisation calculations, followed by kinetic Monte Carlo simulations are used to enumerate the potential energy surfaces for migration of noble metals Pt and Au inside the pore system of siliceous zeolite LTA. The effects of reducing adsorbates CO and H2 are determined. It is found that the two metals differ significantly in the strength and type of interaction with the framework, with strong, framework breaking interactions between Pt and and the zeolite, but only weak dispersive interactions between Au and the zeolite. Adsorbates are found to dramatically interfere with Pt-framework binding, leading to poorer atom-trapping, enhanced metal migration and faster equilibration.

MNDO Study of reaction pathways forSN2 reactions. Menschutkin reaction potential energy surfaces

1984 ◽  
Vol 5 (6) ◽  
pp. 598-605 ◽  
Author(s):  
Jimmy W. Viers ◽  
John C. Schug ◽  
Michael D. Stovall ◽  
Jeffrey I. Seeman
Keyword(s):  
Potential Energy ◽  
Potential Energy Surfaces ◽  
Reaction Pathways ◽  
Reaction Potential ◽  
Energy Surfaces

scholarly journals Energy, orbital and structural stacking landscape of a purine homodimer system

2020 ◽  
Vol 139 (10) ◽  
Author(s):  
Tomasz Sierański
Keyword(s):  
Potential Energy ◽  
Intermolecular Interactions ◽  
Potential Energy Surfaces ◽  
Natural Bond Orbital ◽  
Natural Bond Orbital Analysis ◽  
Energy Sources ◽  
Energy Decomposition ◽  
Energy Surfaces ◽  
Orbital Analysis ◽  
Insight Into

Abstract The multidimensional study, combining the extensive calculations of potential energy surfaces for the parallel-displaced configurations and methods such as energy decomposition and natural bond orbital analysis, has been carried out. The resulted data give an energy, orbital and structural landscapes of this biologically essential system. The balance of the two energy sources, electrostatic and dispersion, is clearly visible. The obtained results, taken as a whole, provide an insight into the hierarchy of intermolecular interactions in the purine system, together with their sources.

THEORETICAL STUDIES ON THE REACTION MECHANISM OF HNCS WITH CH2CH RADICAL

2007 ◽  
Vol 06 (01) ◽  
pp. 1-12 ◽  
Author(s):  
JIAN-HUA XU ◽  
LAI-CAI LI ◽  
YAN ZHENG ◽  
JUN-LING LIU ◽  
XIN WANG
Keyword(s):  
Density Functional Theory ◽  
Reaction Mechanism ◽  
Reaction Mechanisms ◽  
Density Functional ◽  
Hydrogen Transfer ◽  
Main Product ◽  
Reaction Pathways ◽  
Theoretical Studies ◽  
Functional Theory ◽  
Ch Radical

The reaction mechanisms of HNCS with CH 2 CH radical have been investigated by density functional theory (DFT). The geometries and harmonic frequencies of the reactants, intermediates, transition states and products have been calculated at the B3LYP/6-311++G(d,p) level. The results show that the reaction is very complicated. Nine possible reaction pathways were identified. The results show that the most feasible reaction channel is the hydrogen-transfer pathway CH 2 CH + HNCS → IMA1 → TSA1 → CH 2 CHH + NCS . The pathway VIC C-S addition channel ( CH 2 CH + HNCS → TSD5 → IMD4 → TSD9 → CH 2 CHS + CNH ) can also occur easily. Ethene and radical NCS is the main product of the studied reaction, and product P8 ( CH 2 CHS and CNH ) may also be observed. Compared with our previous study on the reaction HNCS + CH 2 CH , the present reaction is easier to proceed.

Catalytic polymerization of naphthalene by HF/BF3 super acid: an ab initio density functional theory study

2018 ◽  
Vol 20 (36) ◽  
pp. 23311-23319 ◽  
Author(s):  
Po-Yu Yang ◽  
Hsing-Yin Chen ◽  
Shin-Pon Ju ◽  
Chia-Lin Chang ◽  
Gao-Shee Leu ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Reaction Mechanism ◽  
Dft Calculations ◽  
Ab Initio ◽  
Density Functional ◽  
Catalytic Polymerization ◽  
Density Functional Theory Study ◽  
Functional Theory ◽  
Detailed Reaction Mechanism ◽  
Super Acid

The detailed reaction mechanism of naphthalene catalytic polymerization by HF/BF3 has been investigated by DFT calculations and the directionality of the naphthalene-derived mesophase molecule has been explained.

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