scholarly journals Direct copolymerization of ethylene with protic comonomers enabled by multinuclear Ni catalysts

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Gang Ji ◽  
Zhou Chen ◽  
Xiao-Yan Wang ◽  
Xiao-Shan Ning ◽  
Chong-Jie Xu ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Acrylic Acid ◽  
Density Functional ◽  
Synergistic Effects ◽  
Nickel Catalysts ◽  
Ionization Mass ◽  
Functional Theory ◽  
Short Chain Length ◽  
Alkenoic Acid ◽  
Catalytic Intermediates

AbstractEthylene/polar monomer coordination copolymerization offers an attractive way of making functionalized polyolefins. However, ethylene copolymerization with industrially relevant short chain length alkenoic acid remain a big challenge. Here we report the efficient direct copolymerization of ethylene with vinyl acetic acid by tetranuclear nickel complexes. The protic monomer can be extended to acrylic acid, allylacetic acid, ω-alkenoic acid, allyl alcohol, and homoallyl alcohol. Based on X-ray analysis of precatalysts, control experiments, solvent-assisted electrospray ionization-mass spectrometry detection of key catalytic intermediates, and density functional theory studies, we propose a possible mechanistic scenario that involves a distinctive vinyl acetic acid enchainment enabled by Ni···Ni synergistic effects. Inspired by the mechanistic insights, binuclear nickel catalysts are designed and proved much more efficient for the copolymerization of ethylene with vinyl acetic acid or acrylic acid, achieving the highest turnover frequencies so far for both ethylene and polar monomers simultaneously.

scholarly journals On the molecular modeling analyses of sodium carboxymethyl cellulose treated with acetic acid

2019 ◽  
Vol 8 (2) ◽  
pp. 553-557 ◽  
Keyword(s):  
Acetic Acid ◽  
Band Gap ◽  
Carboxymethyl Cellulose ◽  
Density Functional ◽  
Band Gap Energy ◽  
Sodium Carboxymethyl Cellulose ◽  
Functional Theory ◽  
Gap Energy ◽  
Model Molecule ◽  
Homo Lumo

Model molecules for sodium carboxymethyl cellulose (Na-CMC) (monomer), glycerol, acetic acid and Na-CMC-glycerol-acetic acid are optimized with Density Functional Theory (DFT) at B3LYP/3-21G*. For the optimized models, total dipole moment (TDM), the highest occupied and lowest unoccupied molecular orbitals (HOMO/LUMO band gap energy), and molecular electrostatic potentials (ESP) are calculated at the same method to give an explanation for the possibility of using Na-CMC-Glycerol-acetic acid model molecule in electrochemical devices, gas sensors and batteries. As a result of the substitution of Na-CMC with glycerol, TDM increased from 7.7141 Debye to 22.4942 Debye which is approximately equal to three times that of Na-CMC. However, HOMO/LUMO band gap energy decreased from 0.9040 eV to 0.5072 eV. After the addition of acetic acid to Na-CMC-glycerol model, TDM increased to24.7270 Debye and HOMO/LUMO band gap energy decreased to 0.4939 eV. Both TDM and HOMO/LUMO band gap energy values are improved by increasing the acetic acid units, where TDM became 25.3510 Debye and HOMO/LUMO band gap energy decreased to 0.3815 eV. The results of ESP indicated that the addition of glycerol and acetic acid to Na-CMC increased the electronegativity of Na-CMC which in turn enhanced its electronic properties.

Tuning of optoelectronic properties of triphenylamines-based donor materials for organic solar cells

2019 ◽  
Vol 18 (07) ◽  
pp. 1950036
Author(s):  
Maria Naeem ◽  
Sobia Jabeen ◽  
Rasheed Ahmad Khera ◽  
Usama Mubashar ◽  
Javed Iqbal
Keyword(s):  
Solar Cells ◽  
Acrylic Acid ◽  
Organic Solar Cells ◽  
Density Functional ◽  
Acid Methyl Ester ◽  
Reorganization Energy ◽  
Optoelectronic Properties ◽  
Functional Theory ◽  
Acid Methyl ◽  
Donor Moiety

In the present study, four molecules have been designed by substituting various acceptor moieties around the triphenylamine donor moiety like 2-cyano acrylic acid (R), 2-methylene malonitrile (M1), 2-cyano acrylic acid methyl ester(M2), 2-(2-methylene-3-oxo-indan-1-ylidene)-malonitrile (M3), 2-(6,7-difluoro-2-methylene-3-oxo-indan-1-ylidene)-malonitrile (M4), respectively. CAM-B3LYP/6-31G (d, p) level of theory by using density functional theory (DFT) has been used for the investigation of optoelectronic properties of four new triphenylamine (TPA)-based donor materials (M1–M4) for organic solar cells. In comparison with the recently reported reference molecule, the optoelectronic properties of designed molecules were evaluated. M4 showed absorption maxima at 520[Formula: see text]nm due to extended conjugation with bridged thiophene group. Results of reorganization energy calculations also favor M4 exhibiting highest transfer rate of hole as depicted from its low reorganization energy of hole ([Formula: see text].

The conversion of CO2 and CH4 to acetic acid over the Au-exchanged ZSM-5 catalyst: a density functional theory study

2012 ◽  
Vol 14 (48) ◽  
pp. 16588 ◽  
Author(s):  
Wasinee Panjan ◽  
Jakkapan Sirijaraensre ◽  
Chompunuch Warakulwit ◽  
Piboon Pantu ◽  
Jumras Limtrakul
Keyword(s):  
Density Functional Theory ◽  
Acetic Acid ◽  
Density Functional ◽  
Density Functional Theory Study ◽  
Functional Theory

scholarly journals Direct carbon-carbon coupling of furanics with acetic acid over Brønsted zeolites

2016 ◽  
Vol 2 (9) ◽  
pp. e1601072 ◽  
Author(s):  
Abhishek Gumidyala ◽  
Bin Wang ◽  
Steven Crossley
Keyword(s):  
Acetic Acid ◽  
Density Functional ◽  
Reaction Rate ◽  
Activation Barrier ◽  
Density Functional Theory Calculations ◽  
Step Change ◽  
Functional Theory ◽  
Transportation Fuels ◽  
Bond Forming ◽  
Direct Acylation

Effective carbon-carbon coupling of acetic acid to form larger products while minimizing CO2emissions is critical to achieving a step change in efficiency for the production of transportation fuels from sustainable biomass. We report the direct acylation of methylfuran with acetic acid in the presence of water, all of which can be readily produced from biomass. This direct coupling limits unwanted polymerization of furanics while producing acetyl methylfuran. Reaction kinetics and density functional theory calculations illustrate that the calculated apparent barrier for the dehydration of the acid to form surface acyl species is similar to the experimentally measured barrier, implying that this step plays a significant role in determining the net reaction rate. Water inhibits the overall rate, but selectivity to acylated products is not affected. We show that furanic species effectively stabilize the charge of the transition state, therefore lowering the overall activation barrier. These results demonstrate a promising new route to C–C bond–forming reactions for the production of higher-value products from biomass.

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