Mechanistic study of the competitiveness between branched and linear polyethylene production on N-arylcyano-β-diketiminate nickel hydride

2020 ◽  
Vol 11 (41) ◽  
pp. 6640-6649
Author(s):  
Daniela E. Ortega ◽  
Diego Cortés-Arriagada ◽  
Oleksandra S. Trofymchuk ◽  
Fabiane M. Nachtigall ◽  
Leonardo S. Santos ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Mechanistic Study ◽  
Linear Polyethylene ◽  
Branched Polyethylene ◽  
Nickel Hydride ◽  
Polyethylene Production

This paper provides a guide to identify and understand the mechanistic origin of the catalytic activity and selectivity in the production of linear and branched polyethylene through a nickel hydride catalyst.

scholarly journals Kinetics and mechanism of meso-tetraphenylporphyriniron(III) chloride (TPP) catalysed oxidation of indole by sodium perborate

2013 ◽  
Vol 15 (2) ◽  
pp. 107-111 ◽  
Author(s):  
D. Kungumathilagam ◽  
K. Karunakaran
Keyword(s):  
Acetic Acid ◽  
Catalytic Activity ◽  
Reaction System ◽  
Kinetic Scheme ◽  
Mechanistic Study ◽  
Radical Mechanism ◽  
Aqueous Acetic Acid ◽  
Sodium Perborate ◽  
Acetic Acid Medium ◽  
Catalysed Oxidation

Developing catalyst is very significant for biologically important reactions which yield products, used as drugs. Mechanistic study on meso-tetraphenylporphyriniron(III) chloride (TPP) catalysed oxidation of indole by sodium perborate in aqueous acetic acid medium have been carried out. The reaction follows a fractional order with respect to substrate and catalyst. The order with respect to oxidant was found to be one. Increase in the percentage of acetic acid and increase in the concentration of [H+] decreased the rate. The reaction fails to initiate polymerization, and a radical mechanism is ruled out. Activation and thermodynamic parameters have been computed. A suitable kinetic scheme based on these observations has been proposed. Significant catalytic activity is observed for the reaction system in the presence of TPP.

Catalytic Activity of Cobalt Nanoparticles for Dye and 4-Nitro Phenol Degradation: A Kinetic and Mechanistic Study

2017 ◽  
Vol 49 (6) ◽  
pp. 438-454 ◽  
Author(s):  
Mohammad Naved Khan ◽  
Ommer Bashir ◽  
Tabrez Alam Khan ◽  
Shaeel Ahmed Al-Thabaiti ◽  
Zaheer Khan
Keyword(s):  
Catalytic Activity ◽  
Phenol Degradation ◽  
Cobalt Nanoparticles ◽  
Mechanistic Study

scholarly journals Mechanistic Study of Silane Alcoholysis Reactions with Self-Assembled Monolayer-Functionalized Gold Nanoparticle Catalysts

Catalysts ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 908
Author(s):  
Katsuhiro Isozaki ◽  
Tomoya Taguchi ◽  
Kosuke Ishibashi ◽  
Takafumi Shimoaka ◽  
Wataru Kurashige ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Metallic Nanoparticles ◽  
Molecular Structures ◽  
Critical Parameters ◽  
Mechanistic Study ◽  
Self Assembled Monolayer ◽  
Mechanistic Investigation ◽  
Self Assembled ◽  
20 Nm ◽  
Silane Alcoholysis

The self-assembled monolayer (SAM)-modified metallic nanoparticles (MNPs) often exhibit improved chemoselectivity in various catalytic reactions by controlling the reactants’ orientations adsorbed in the SAM; however, there have been a few examples showing that the reaction rate, i.e., catalytic activity, is enhanced by the SAM-modification of MNP catalysts. The critical parameters that affect the catalytic activity, such as the supports, nanoparticle size, and molecular structures of the SAM components, remain uninvestigated in these sporadic literature precedents. Here, we report the mechanistic investigation on the effects of those parameters on the catalytic activity of alkanethiolate SAM-functionalized gold nanoparticles (AuNPs) toward silane alcoholysis reactions. The evaluation of the catalytic reaction over two-dimensionally arrayed dodecanethiolate SAM-functionalized AuNPs with different supports revealed the electronic interactions between AuNPs and the supports contributing to the rate enhancement. Additionally, an unprecedented size effect appeared—the AuNP with a 20 nm radius showed higher catalytic activity than those at 10 and 40 nm. Infrared reflection–absorption spectroscopy revealed that the conformational change of alkyl chains of the SAM affects the entrapment of reactants and products inside the SAM, and therefore brings about the acceleration effect. These findings provide a guideline for further applying the SAM-functionalization technique to stereoselective organic transformations with designer MNP catalysts.

Facet dependent catalytic activity of Pd nanocrystals for the remedy of organic Pollutant: A mechanistic study

2021 ◽  
Vol 570 ◽  
pp. 150775
Author(s):  
Swarnalata Swain ◽  
Bhamy Maithry Shenoy ◽  
Prangya Bhol ◽  
Sudesh Yadav ◽  
Satya Ranjan Jena ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Organic Pollutant ◽  
Mechanistic Study

(Diphosphane monosulfide)platinum(II) Complexes for Hydroformylation Reactions: Their Catalytic Activity and a High-Pressure NMR Mechanistic Study

2006 ◽  
Vol 2006 (11) ◽  
pp. 2268-2276 ◽  
Author(s):  
Antonio Lofù ◽  
Piero Mastrorilli ◽  
Cosimo F. Nobile ◽  
Gian P. Suranna ◽  
Piero Frediani ◽  
...  
Keyword(s):  
High Pressure ◽  
Catalytic Activity ◽  
Mechanistic Study

Mechanistic details of ethylene polymerization reaction using methallyl nickel(ii) catalysts

2018 ◽  
Vol 20 (35) ◽  
pp. 22915-22925 ◽  
Author(s):  
Daniela E. Ortega ◽  
Diego Cortés-Arriagada ◽  
Alejandro Toro-Labbé
Keyword(s):  
Ethylene Polymerization ◽  
Polymerization Reaction ◽  
Mechanistic Study ◽  
Polyethylene Production ◽  
High Degree

We present a mechanistic study of the ligand functionalization of bulky boron co-activators on neutral methallyl Ni(ii) catalysts for polyethylene production. This provides a blueprint for the development and design of catalysts with a high degree of tunability in a more efficient way.

scholarly journals Enhanced Catalytic Activity in the Oxidative Synthesis of Benzoxazoles by Tuning Local Electron Charge Densities in N-doped sp3@sp2 Hybrid Nanodiamond

2021 ◽  
Author(s):  
Qingqing Gu ◽  
Yanan Zhou ◽  
Rui Huang ◽  
Yangming Lin ◽  
Chi Xu ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Drug Targets ◽  
Active Sites ◽  
Mechanistic Study ◽  
Charge Densities ◽  
Local Electronic Structure ◽  
Good Catalytic Activity ◽  
Activity Enhancement ◽  
First Time ◽  
Pyridinic N

Abstract Metal-free nanocarbons among other unique characteristics, offer the possibility of tuning the local electronic structure of the active sites allowing to identify precisely how to enhance the catalytic activity. Hence N-doped sp3@sp2 hybrid nanocarbons are studied here for the catalytic oxidative synthesis of a broad series of drug-related compounds (23 examples), like 2-substituted benzoxazoles, benzothiazoles and benzimidazoles under mild conditions and they show good catalytic activity and reusability which is comparable to homogeneous /heterogeneous metal-based catalysts. We demonstrate for the first time that the electron-donating capability and intrinsic catalytic activity of pyridinic N and neighboring C atoms can be enhanced by increasing up to c.a. 3 layers of sp2 C over the N-doped sp3@sp2 nanocarbon, which is evidenced by the KPFM measurements and DFT calculations. The mechanistic study suggests that the O2 could be activated to O2•−, which could subsequently react with abstracted H along with the formation of H2O2. This study provides a methodology of applying carbocatalysts for the synthesis of complex drug targets and shed light on the origin of the intrinsic catalytic activity enhancement of the pyridinic N by regulating the sp2 C layers of the catalysts.

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