scholarly journals Theoretical study on the reaction mechanism of “ligandless” Ni-catalyzed hydrodesulfurization of aryl sulfide

RSC Advances ◽  
2017 ◽  
Vol 7 (81) ◽  
pp. 51475-51484 ◽  
Author(s):  
Sheng Fang ◽  
Meiyan Wang ◽  
Jingjing Liu ◽  
Bingwen Li ◽  
Jing-yao Liu

The reaction mechanism of Ni(COD)2 catalyzed hydrodesulfurization of aryl sulfide PhSMe with HSiMe3 has been predicted to have two competitive reaction pathways, with or without PhSMe spectator ligand, by using density functional theory methods.

2007 ◽  
Vol 06 (01) ◽  
pp. 1-12 ◽  
Author(s):  
JIAN-HUA XU ◽  
LAI-CAI LI ◽  
YAN ZHENG ◽  
JUN-LING LIU ◽  
XIN WANG

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.


2019 ◽  
Vol 21 (3) ◽  
pp. 1384-1392 ◽  
Author(s):  
De-Ming Rao ◽  
Tao Sun ◽  
Yu-Sen Yang ◽  
Pan Yin ◽  
Min Pu ◽  
...  

A density functional theory study has been carried out to investigate the mechanism of acetylene hydrogenation on six surfaces of Ni–Sn IMCs, and the geometric effects towards ethylene selectivity was revealed.


Author(s):  
Yang Wang ◽  
Yue Liu ◽  
Kaili Gong ◽  
Han Zhang ◽  
Yu Lan ◽  
...  

A theoretical study of the mechanism of the N-heterocyclic carbene (NHC)-catalyzed C-S bond cleavage and reconstruction reaction of unsaturated thioesters was conducted using density functional theory (DFT). The origin of...


RSC Advances ◽  
2016 ◽  
Vol 6 (91) ◽  
pp. 88277-88286 ◽  
Author(s):  
Laicai Li ◽  
Wei Wei ◽  
Wei Wang ◽  
Xiaolan Wang ◽  
Lin Zhang ◽  
...  

The reaction mechanism of the selective hydrogenation of cinnamaldehyde catalyzed by pure Pt clusters and Co-doped Pt clusters was studied by the density functional theory.


2019 ◽  
Vol 16 (5) ◽  
pp. 392-395
Author(s):  
Kamlesh Sharma

The mechanism of addition of nucleophiles to the π-acid complexed alkynes has been studied successfully by the assessment of energy of intermediates and activation parameters. To elucidate the origin of stereoselectivity and predict the reaction pathways, the geometry optimizations of reactants, products, intermediates and transition states, were calculated by using density functional theory (DFT) at the B3LYP/6-31+G(d) method. The reaction mechanism of hydration of alkynes in the catalyzed synthesis of bis-spiroketal by DFT calculations is explored. The pyranyl enol ether was formed regioselectively by the first ring closure. Further, bis-enol ether was formed by second 6-exodig addition. Then, dehydration, followed by dehydrative ring closure finally gave bis-spiroketal product. It is concluded that one of the most feasible reaction pathways comprises pyranyl enol ether and bis-enol ether formation as intermediates. The final cyclization step of product formation is endothermic. In terms of stereochemistry, the trans-product is found to be energetically more stable than cisproduct and hence supports the electivity of the reaction.


2021 ◽  
Author(s):  
Ling Zhu ◽  
Lin Zhang ◽  
Zuoyin Yang ◽  
Min Pu ◽  
Ming Lei

Herein density functional theory (DFT) method was employed to explore the reaction mechanism of selective hydroboration of α,β-unsaturated carbonyl compounds catalyzed by the metal-free complex, 1,3,2-diazaphospholene (DAP). The whole reaction...


2020 ◽  
Vol 9 (1) ◽  
pp. 73-80
Author(s):  
Hue Van Thi Minh ◽  
Lan Phung Thi ◽  
Ha Nguyen Thi Thu ◽  
Cam Le Minh ◽  
Ha Nguyen Ngoc

The methanation of carbon dioxide over Ni5 supported on activated carbon (Ni5/AC) was studied by using density functional theory and climbing image – nudged elastic band methods. A reaction diagram for the formation of methane via CO or HCOO species, which consists of 14 reaction steps was proposed. The reaction energy and activation energy for the overall steps involved in the reaction process were calculated and analyzed. Following the proposed mechanism possible carbon byproducts of the CO2 methanation reaction are CO and HCHO. Formation of these products can occur at high temperatures, but it is more thermodynamically difficult than formation of CH4. The formation of CH4 is more preferably occur via the CO pathway than the HCOO pathway.


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