A dynamic reaction coordinate approach to ab initio reaction pathways: Application to the 1,5 hexadiene Cope rearrangement

1990 ◽  
Vol 93 (8) ◽  
pp. 5902-5911 ◽  
Author(s):  
S. A. Maluendes ◽  
M. Dupuis
Keyword(s):  
Ab Initio ◽  
Reaction Coordinate ◽  
Reaction Pathways ◽  
Cope Rearrangement ◽  
Dynamic Reaction

Ab Initio Computational Study of the Allenyl Cope Rearrangement ofsyn-7-Allenylnorbornene

1999 ◽  
Vol 121 (51) ◽  
pp. 12029-12034 ◽  
Author(s):  
James A. Duncan ◽  
Joseph K. Azar ◽  
J. Callan Beathe ◽  
Scott R. Kennedy ◽  
Carolyn M. Wulf
Keyword(s):  
Ab Initio ◽  
Computational Study ◽  
Cope Rearrangement

Dynamic Reaction Coordinate Analysis: An Application to SiH4 + H- .fwdarw. SiH5-

1995 ◽  
Vol 99 (21) ◽  
pp. 8462-8471 ◽  
Author(s):  
Tetsuya Taketsugu ◽  
Mark S. Gordon
Keyword(s):  
Reaction Coordinate ◽  
Dynamic Reaction

[3,3] Sigmatropic Rearrangement of Some Fluorinated 1,5-Hexadienes

2002 ◽  
Vol 67 (10) ◽  
pp. 1517-1532 ◽  
Author(s):  
William R. Dolbier ◽  
Keith W. Palmer ◽  
Feng Tian ◽  
Piotr Fiedorow ◽  
Andrzej Zaganiaczyk ◽  
...  
Keyword(s):  
Experimental Data ◽  
Ab Initio ◽  
Transition States ◽  
Activation Parameters ◽  
Sigmatropic Rearrangement ◽  
Semiempirical Methods ◽  
Cope Rearrangement ◽  
Computational Studies ◽  
Stepwise Mechanism ◽  
Radical Intermediates

Fluorine atoms incorporated into 1,5-hexadiene molecule should influence the kinetic as well as the thermodynamic parameters of [3,3] sigmatropic rearrangement (Cope rearrangement). Within few decades is has been documented that this transformation proceeds in a concerted manner, rather than stepwise with some radical intermediates involved. Few new terminally fluorinated 1,5-hexadienes (compounds 3, 5A, 7, 9 and 5B) have been synthesized. The activation parameters of rearrangement have been determined and compared with those known for hydrocarbon analogues. While systems developing chair-like transition states (compounds 3 and 5) showed close similarity with hydrocarbon analogues (compound 1), those developing boat-like transition states (compounds 7, 9 and 5B) may proceed through radical stepwise mechanism. Computational studies of the transition states were carried out, showing that only ab initio methods (MP2 and especially DFT) can give approximate correlation with experimental data, whereas in the case of hydrocarbon analogues even simple semiempirical methods (AM1) were reliable enough to reproduce experimental results.

Ab initio mechanism revealing for tricalcium silicate dissolution

2021 ◽  
Author(s):  
Yunjian Li ◽  
Hui Pan ◽  
Xing Ming ◽  
Zongjin Li
Keyword(s):  
Free Energy ◽  
Ab Initio ◽  
Calcium Ions ◽  
Tricalcium Silicate ◽  
Proton Exchange ◽  
Reaction Pathways ◽  
Ab Initio Molecular Dynamics ◽  
Energy Barriers ◽  
Silicate Dissolution ◽  
Quantitative Analyses

Abstract Dissolution of mineral in water is ubiquitous in nature and industry, especially for the calcium silicate species. However, the behavior of such a complex chemical reaction is still unclear at atomic level. Here, we show that the ab initio molecular dynamics and metadynamics simulations enable quantitative analyses of reaction pathways, and the thermodynamics and kinetics of calcium ion dissolution from the tricalcium silicate (Ca3SiO5) surface. The calcium sites with different coordination environment leads to different reaction pathways and free energy barriers. The low free energy barriers lead to that the detachment of calcium ions is a ligand exchange and auto-catalytic process. Moreover, the water adsorption, proton exchange and diffusion of water into the surface layer accelerate the leaching of calcium ions from the surface step by step. The discovery in this work thus would be a landmark for revealing the mechanism of cement hydration.

scholarly journals Ab Initio Study of CO2 Capture Mechanisms in Monoethanolamine Aqueous Solution: Reaction Pathways from Carbamate to Bicarbonate

2013 ◽  
Vol 37 ◽  
pp. 400-406 ◽  
Author(s):  
Yoichi Matsuzaki ◽  
Hidetaka Yamada ◽  
Firoz A. Chowdhury ◽  
Takayuki Higashii ◽  
Shingo Kazama ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Ab Initio ◽  
Co2 Capture ◽  
Reaction Pathways ◽  
Ab Initio Study ◽  
Solution Reaction

Static and dynamic reaction pathways involved in the reaction of O− and CH3F

2010 ◽  
Vol 947 (1-3) ◽  
pp. 1-8 ◽  
Author(s):  
Feng Yu ◽  
Lixia Wu ◽  
Shilin Liu ◽  
Xiaoguo Zhou
Keyword(s):  
Reaction Pathways ◽  
Dynamic Reaction

scholarly journals Terpenoids from Neolitsea Dealbata

2008 ◽  
Vol 3 (2) ◽  
pp. 1934578X0800300 ◽  
Author(s):  
Xiujun Wu ◽  
Bernhard Vogler ◽  
Betsy R. Jackes ◽  
William N. Setzer
Keyword(s):  
Ab Initio ◽  
Bark Extract ◽  
Cope Rearrangement ◽  
Phytochemical Investigation ◽  
First Time

A phytochemical investigation of the crude chloroform bark extract of Neolitsea dealbata from Paluma, north Queensland, Australia, revealed the two common triterpenoids, taraxerone and taraxerol, as well as three furanogermacranolide sesquiterpenoids, linderadine, linderalactone, and pseudoneolinderane. These compounds are reported for the first time from this plant. An ab initio investigation (DFT, B3LYP/6-31G* and post HF, MP2/6-31G**) of the Cope rearrangement of linderalactone has been carried out.

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