Controlled ring-opening polymerization of ε-caprolactone initiated by in situ formed yttrium trisalicylaldimine complexes, and their study by density functional theory

2011 ◽  
Vol 60 (12) ◽  
pp. 1745-1752 ◽  
Author(s):  
Xufeng Ni ◽  
Zhenhua Liang ◽  
Jun Ling ◽  
Xue Li ◽  
Zhiquan Shen
Keyword(s):  
Density Functional Theory ◽  
Ring Opening ◽  
Density Functional ◽  
Ring Opening Polymerization ◽  
Functional Theory

A Density Functional Theory Study on the Ring-Opening Polymerization of D-Lactide Catalyzed by a Bifunctional-Thiourea Catalyst

2009 ◽  
Vol 62 (2) ◽  
pp. 157 ◽  
Author(s):  
Rong-Xiu Zhu ◽  
Ruo-Xi Wang ◽  
Dong-Ju Zhang ◽  
Cheng-Bu Liu
Keyword(s):  
Density Functional Theory ◽  
Ring Opening ◽  
Density Functional ◽  
Population Analysis ◽  
Density Functional Theory Calculations ◽  
Ring Opening Polymerization ◽  
Acyl Transfer ◽  
Frontier Molecular Orbital ◽  
Functional Theory ◽  
Elimination Pathway

The thiourea-catalyzed methanolysis of d-lactide, a model system for the initiation and propagation of the organocatalyzed ring-opening polymerization (ROP) of lactide, has been studied by performing density functional theory calculations. Both the catalyzed and uncatalyzed reactions are explored along two possible pathways: one involves the stepwise addition–elimination pathway and the other is related to the concerted pathway. It is found that the reaction without the presence of the catalyst is difficult because the barrier involved is as high as 176 kJ mol–1. With the aid of a thiourea catalyst, the barrier is reduced to 88 kJ mol–1 with a preference for the stepwise addition–elimination mechanism over the concerted one. The role of the catalyst has been rationalized by analyzing the frontier molecular orbital interactions between the catalyst and substrates and by performing natural population analysis. Finally, another mechanism involving acyl transfer is discussed for the thiourea-catalyzed ROP.

scholarly journals Rationalizing the Reactivity of Mixed Allyl Rare-Earth Borohydride Complexes with DFT Studies

Catalysts ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 820
Author(s):  
Sami Fadlallah ◽  
Jashvini Jothieswaran ◽  
Iker Del Rosal ◽  
Laurent Maron ◽  
Fanny Bonnet ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Rare Earth ◽  
Ring Opening ◽  
Density Functional ◽  
Ring Opening Polymerization ◽  
Polymerization Reaction ◽  
Experimental Investigations ◽  
Dft Studies ◽  
Functional Theory ◽  
Activation Barriers

The reactivity of rare-earth complexes RE(BH4)2(C3H5)(THF)x (RE = La, Nd, Sm, Y, Sc) toward the Ring-Opening Polymerization (ROP) of ε-caprolactone (ε-CL) was rationalized by Density Functional Theory (DFT) calculations. Even if the polymerization reaction can be initiated by both RE-(BH4) and RE-allyl bonds, experimental investigations have shown that the initiation via the borohydride ligand was favored, as no allyl group could be detected at the chain-end of the resulting polymers. DFT studies could confirm these observations, as it was highlighted that even if the activation barriers are both accessible, the allyl group is not active for the ROP of ε-CL due to the formation of a highly stable intermediate that disfavors the subsequent ring-opening.

scholarly journals Density functional theoretical studies on the ring-opening polymerization mechanism of oxetane cation series compounds

RSC Advances ◽  
2017 ◽  
Vol 7 (78) ◽  
pp. 49626-49632
Author(s):  
Hai-Xia Wang ◽  
Min Pu ◽  
Yu-Cheng Ding
Keyword(s):  
Density Functional Theory ◽  
Ab Initio ◽  
Ring Opening ◽  
Density Functional ◽  
Ring Opening Polymerization ◽  
Basis Set ◽  
Theoretical Studies ◽  
Functional Theory ◽  
Polymerization Mechanism

The mechanism of ring-opening polymerization of oxetane cation series compounds was investigated using the B3LYP and MP2 methods of density functional theory andab initiomethods, at the basis set levels of 6-31G(d,p) and 6-311++G(d,p).

In Situ Exsolved Au Nanoparticles from Perovskite Oxide for Efficient Epoxidation of Styrene

2021 ◽  
Author(s):  
Yang Gao ◽  
Xing Chen ◽  
Shuqi Hu ◽  
Shiguo Zhang
Keyword(s):  
Density Functional Theory ◽  
Thermodynamic Analysis ◽  
Density Functional ◽  
Au Nanoparticles ◽  
Oxide Catalyst ◽  
Density Functional Theory Calculations ◽  
Average Diameter ◽  
Perovskite Oxide ◽  
Functional Theory

Au-doped SrTiO3 perovskite oxide catalyst (Sr0.995Au0.005TiO3-δ) has been designed and synthesized based on thermodynamic analysis and density functional theory calculations. During reduction, Au nanoparticles with an average diameter of 2...

Predicting the origin of selectivity in NHC-catalyzed ring opening of formylcyclopropane: a theoretical investigation

2021 ◽  
Author(s):  
Yang Wang ◽  
Yan Qiao ◽  
Yu Lan ◽  
Donghui Wei
Keyword(s):  
Density Functional Theory ◽  
Theoretical Investigation ◽  
Ring Opening ◽  
Density Functional ◽  
Functional Theory

Using density functional theory, we investigated the origin of selectivity in the N-heterocyclic carbene (NHC)-catalyzed transformation of formylcyclopropane with an alkylidene oxindole.

Investigation of Structural Evolution of Li1.1V3O8 by In Situ X-ray Diffraction and Density Functional Theory Calculations

2017 ◽  
Vol 29 (5) ◽  
pp. 2364-2373 ◽  
Author(s):  
Qing Zhang ◽  
Alexander B. Brady ◽  
Christopher J. Pelliccione ◽  
David C. Bock ◽  
Andrea M. Bruck ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Structural Evolution ◽  
Density Functional Theory Calculations ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray
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