Distinguishing the Early and Late Transition States and Exploring the Validity of σ → σ*#, σ# → σ*, and σ → π*COConcepts in Diastereoselection from NBO Analysis

2006 ◽  
Vol 71 (11) ◽  
pp. 4178-4182 ◽  
Author(s):  
Veejendra K. Yadav ◽  
Archana Gupta ◽  
Rengarajan Balamurugan ◽  
Vardhineedi Sriramurthy ◽  
Naganabonia Vijaya Kumar
Keyword(s):  
Transition States ◽  
Nbo Analysis ◽  
Late Transition

scholarly journals Assessing the effective factors affecting the conformational preferences and the early and late transition states of the unimolecular retro-ene decomposition reactions of ethyl cyanate, ethyl thiocyanate and ethyl selenocyanate

RSC Advances ◽  
2017 ◽  
Vol 7 (37) ◽  
pp. 22757-22770 ◽  
Author(s):  
Hooshang Atabaki ◽  
Davood Nori-Shargh ◽  
Mohamad Momen-Heravi
Keyword(s):  
Transition States ◽  
Factors Affecting ◽  
Effective Factors ◽  
Decomposition Reactions ◽  
Barrier Heights ◽  
Conformational Preferences ◽  
Late Transition

The variations of Δ[(HCGAE(X3–C4weakening) – HCGAE(X3–C4strengthening)] parameters correlate well with the variations of the retro-ene decomposition reactions barrier heights going from compound1to compound3.

New mechanistic criterion for early and late transition states

1976 ◽  
Vol 98 (24) ◽  
pp. 7819-7821 ◽  
Author(s):  
Rolf Huisgen ◽  
Reinhard Schug
Keyword(s):  
Transition States ◽  
Late Transition

scholarly journals New insights on the theoretical study of hydrolysis mechanism of carbon disulfide (CS2) at low temperature: A density functional theory study

2022 ◽  
Author(s):  
Yue Wang ◽  
Guijian Zhang ◽  
Xin Shi ◽  
Ming Deng ◽  
Lihong Tang ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Exothermic Reaction ◽  
Transition States ◽  
Nbo Analysis ◽  
Functional Theory ◽  
Hydrolysis Mechanism ◽  
Rate Determining Step ◽  
Kinetics Of ◽  
Hydrolysis Of

Abstract Density functional theory (DFT) is used to investigate the two-step hydrolysis mechanism of CS2. By optimizing the structure of reactants, intermediates, transition states, and products, the conclusion shows that the first step of CS2 (CS2 reacts with H2O first to form COS intermediate); The second step (COS intermediate reacts with H2O to form H2S and CO2). Therefore, hydrogen migration is crucial to the mechanism of CS2 hydrolysis. In the first step of the reaction, the rate-determining step in both the single C=S path and the double C=S path has a higher barrier of 199.9 kJ/mol, but the 127.9 kJ/mol barrier in the double C=S path has a lower barrier of 142.8 kJ/mol in the single C=S path. So the double C=S path is better. Similarly, the order of the barriers for the three paths in the second reaction is C=S path < C=S path and C=O path < C=O path. So the C=S path is better. Also, to further explore the reaction of CS2 hydrolysis, the natural bond orbital (NBO) analysis of the transition states was carried out. Besides, to further explain which reaction path is better, the hydrolysis kinetics of CS2 was analyzed. It was found that the hydrolysis of CS2 was an exothermic reaction, and the increase in temperature was unfavorable to the reaction. During the hydrolysis of CS2, the six reaction paths are parallel and competitive. The results will provide a new way to study the catalytic hydrolysis of CS2.

Sign in / Sign up

Export Citation Format

Share Document