Systematic Investigation of the Catalytic Cycle of a Single Site Ruthenium Oxygen Evolving Complex Using Density Functional Theory

2011 ◽  
Vol 115 (29) ◽  
pp. 9280-9289 ◽  
Author(s):  
Thomas F. Hughes ◽  
Richard A. Friesner
2019 ◽  
Vol 6 (12) ◽  
pp. 3482-3492 ◽  
Author(s):  
Yun-Jie Chu ◽  
Xue-Mei Chen ◽  
Chun-Guang Liu

The silanol-functionalized POM-supported single-site Os oxide catalyst has been theoretically considered for epoxidation of propylene in the presence of dioxygen based on density functional theory calculations.


Catalysts ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 359 ◽  
Author(s):  
Hanwei Li ◽  
Mingliang Luo ◽  
Guohong Tao ◽  
Song Qin

Computational investigations on the bisphospholanoethane (BPE)-ligated Cu-catalyzed enantioselective addition of enynes to ketones were performed with the density functional theory (DFT) method. Two BPE-mesitylcopper (CuMes) catalysts, BPE-CuMes and (S,S)-Ph-BPE–CuMes, were employed to probe the reaction mechanism with the emphasis on stereoselectivity. The calculations on the BPE-CuMes system indicate that the active metallized enyne intermediate acts as the catalyst for the catalytic cycle. The catalytic cycle involves two steps: (1) ketone addition to the alkene moiety of the metallized enyne; and (2) metallization of the enyne followed by the release of product with the recovery of the active metallized enyne intermediate. The first step accounts for the distribution of the products, and therefore is the stereo-controlling step in chiral systems. In the chiral (S,S)-Ph-BPE–CuMes system, the steric hindrance is vital for the distribution of products and responsible for the stereoselectivity of this reaction. The steric hindrance between the phenyl ring of the two substrates and groups at the chiral centers in the ligand skeleton is identified as the original of the stereoselectivity for the titled reaction.


2019 ◽  
Author(s):  
Alexander Tygesen ◽  
Jinhyun Chang ◽  
Tejs Vegge ◽  
Juan Maria García Lastra

Computational study of anionic redox processes in Li2MnO3, and newly developed methods for identifying and studying the evolution of anionic redox using density functional theory (DFT). A method for identifying localized anionic redox species is applied to a set of structures relaxed using the VASP software. A preconditioning scheme is presented to promote the formation of peroxo-like oxygen species, and study the formation and evolution of anionic redox.


2016 ◽  
Vol 18 (20) ◽  
pp. 13830-13843 ◽  
Author(s):  
Seema Gautam ◽  
Abir De Sarkar

Vinyl isocyanide formation: adsorption of C2H2 and HCN in succession on the Au9 cluster; towards polymerization: clustering of C2H2 on Au9.


2016 ◽  
Vol 94 (12) ◽  
pp. 1028-1037 ◽  
Author(s):  
Zhe Li ◽  
Miaoren Xia ◽  
Russell J. Boyd

The mechanism of the iridium-catalyzed functionalization of a primary C–H bond at the γ position of an alcohol 5 is investigated by density functional theory (DFT) calculations. A new IrIII–IrV mechanism is found to be more feasible than the previously reported IrI–IrIII mechanism. 10 In the IrIII–IrV mechanism, the reaction begins with the initial formation of (Me4phen)IrIII(H)[Si(OR)Et2]2 from the catalyst precursor, [Ir(cod)OMe]2 (cod = 1,5-cyclooctadiene). The catalytic cycle includes five steps: (1) the insertion of norbornene into the Ir–H bond to produce (Me4phen)IrIII(norbornyl)[Si(OR)Et2]2 (R = –CH(C2H5)C3H7); (2) the Si–H oxidative addition of HSi(OR)Et2 to form (Me4phen)IrVH(norbornyl)[Si(OR)Et2]3; (3) the reductive elimination of norbornane to furnish (Me4phen)IrIII[Si(OR)Et2]3; (4) the intramolecular C–H activation of the primary C–H bond at the γ position; and (5) the Si–C reductive elimination to produce the final product and regenerate the catalyst. The highest barrier in the IrIII–IrV mechanism is 7.3 kcal/mol lower than that of the IrI–IrIII mechanism. In addition, the regioselectivity of the C–H activation predicted by this new IrIII–IrV mechanism is consistent with experimental observation.


Sign in / Sign up

Export Citation Format

Share Document