Theoretical and Experimental Studies of C–C versus C–O Bond Scission of Ethylene Glycol Reaction Pathways via Metal-Modified Molybdenum Carbides

ACS Catalysis ◽  
2014 ◽  
Vol 4 (5) ◽  
pp. 1409-1418 ◽  
Author(s):  
Weiting Yu ◽  
Michael Salciccioli ◽  
Ke Xiong ◽  
Mark A. Barteau ◽  
Dionisios G. Vlachos ◽  
...  
Keyword(s):  
Ethylene Glycol ◽  
Experimental Studies ◽  
Reaction Pathways ◽  
Molybdenum Carbides ◽  
Bond Scission

scholarly journals Microwave-assisted lignin liquefaction in hydrazine and ethylene glycol: Reaction pathways via response surface methodology

2021 ◽  
Vol 27 ◽  
pp. e00245
Author(s):  
Divine B. Nde ◽  
Mohamad Barekati-Goudarzi ◽  
Pranjali D. Muley ◽  
Lavrent Khachatryan ◽  
Dorin Boldor
Keyword(s):  
Response Surface Methodology ◽  
Ethylene Glycol ◽  
Response Surface ◽  
Reaction Pathways ◽  
Microwave Assisted

Mechanisms of Electrochemical N2 Splitting by a Molybdenum Pincer Complex

2021 ◽  
Author(s):  
Quinton Bruch ◽  
Santanu Malakar ◽  
Alan Goldman ◽  
Alexander Miller
Keyword(s):  
Electrode Surface ◽  
Redox Reactions ◽  
Catalytic Reduction ◽  
Reaction Pathways ◽  
Bulk Solution ◽  
Mechanistic Study ◽  
Pincer Ligands ◽  
Computational Studies ◽  
Pincer Complex ◽  
Bond Scission

Molybdenum complexes supported by tridentate pincer ligands are exceptional catalysts for dinitrogen fixation using chemical reductants, but little is known about their prospects for electrochemical reduction of dinitrogen. The viability of electrochemical N2 binding and splitting by a molybdenum(III) pincer complex, (pyPNP)MoBr3 (pyPNP = 2,6-bis(tBu2PCH2)-C5H3N)), is established in this work, providing a foundation for a detailed mechanistic study of electrode-driven formation of the nitride complex (pyPNP)Mo(N)Br. Electrochemical kinetic analysis, optical and vibrational spectroelectrochemical monitoring, and computational studies point to two reaction pathways: in the “reaction layer” pathway, the molybdenum(III) precursor is reduced by 2e– and generates a bimetallic molybdenum(I) Mo2(-N2) species capable of N–N bond scission. In the “bulk solution” pathway the precursor is reduced by 3e– at the electrode surface to generate molybdenum(0) species that undergo chemical redox reactions via comproportionation in the bulk solution away from the electrode surface to generate the same bimetallic molybdenum(I) species capable of N2 cleavage. The comproportionation reactions reveal the surprising intermediacy of dimolybdenum(0) complex trans,trans-[(pyPNP)Mo(N2)2](-N2) in N2 splitting pathways. The same “over-reduced” molybdenum(0) species was also found to cleave N2 upon addition of lutidinium, an acid frequently used in catalytic reduction of dinitrogen.

scholarly journals Experimental studies on toxicity of ethylene glycol alkyl ethers in Japan.

1984 ◽  
Vol 57 ◽  
pp. 75-84 ◽  
Author(s):  
K Nagano ◽  
E Nakayama ◽  
H Oobayashi ◽  
T Nishizawa ◽  
H Okuda ◽  
...  
Keyword(s):  
Ethylene Glycol ◽  
Experimental Studies ◽  
Alkyl Ethers

Ambident reactivity in the reaction of phenoxide ion with 2-N-(2′,4′-dinitrophenyl)- and 2-N-(4′-nitrophenyl)-4,6-dinitrobenzotriazole 1-oxides, new superelectrophiles

1988 ◽  
Vol 66 (7) ◽  
pp. 1712-1719 ◽  
Author(s):  
Erwin Buncel ◽  
Julian M. Dust
Keyword(s):  
Activation Energy ◽  
Adduct Formation ◽  
Reaction Pathways ◽  
Resonance Spectroscopy ◽  
The Novel ◽  
Reaction Series ◽  
Bond Scission ◽  
Energy Reaction ◽  
Successive Removal ◽  
Ambident Nucleophile

Reaction of the novel superelectrophiles 2-N-(2′,4′-dinitrophenyl)- and 2-N-(4′-nitrophenyl)-4,6-dinitrobenzotriazole 1-oxides, 3, and 4, possessing two electrophilic centres, with the ambident nucleophile potassium phenoxide in (CD3)2SO was followed by 400 MHz 1H nuclear magnetic resonance spectroscopy. A dichotomy in the reaction pathways has been observed. With MeO−, attack at C-7 leads to reversible adduct formation, while attack at C-1′ results in irreversible N-2: C-1′ bond scission via the metastable C-1′ adduct. In contrast, the reaction of 3 and 4 with PhO− proceeds by a two-pronged attack: formation of C-7 carbon-bonded phenoxide adducts via the ortho and para carbon sites, and oxygen-based cleavage products by attack at the C-1′ position, accompanied by N-2:C-1′ bond scission, in accord with the ambident reactivity of PhO−. Significantly, in this case reaction of both C-7 and C-1′ is effectively irreversible. Moreover, the reaction of phenoxide with either 3 or 4 shows striking differences compared to the reaction of PhO− with 2-N-(picryl)-4,6-dinitrobenzotriazole 1-oxide, 1. Reaction of PhO− with 1 resulted only in O-attack at C-1′ and N-2:C-1′ bond scission; there was no evidence for C-7 adduct formation via O- or C-attack. This marked difference in behaviour can be attributed to the decreased susceptibility to C-1′ attack exhibited by 3 and 4 as compared to 1 and arises from the successive removal of electron-withdrawing nitro groups from the 2-N′-nitroaryl moiety in the series 1 → 3 → 4. The reactions are discussed on the basis of selectivity considerations and an activation energy/reaction coordinate profile comparing the pathways for both C-attack at C-7 and O-attack at C-l′ as electrophilicity (delocalizability) is progressively modulated in the reaction series.

Forced-Convection Condensation of Ethylene Glycol on Integral-Fin Tubes

2004 ◽  
Author(s):  
Satesh Namasivayam ◽  
Adrian Briggs
Keyword(s):  
Ethylene Glycol ◽  
Forced Convection ◽  
Experimental Studies ◽  
Heat Fluxes ◽  
Slight Reduction ◽  
Enhancement Ratio ◽  
Vapor Velocity ◽  
Wide Range ◽  
Plain Tube ◽  
Fin Tubes

This paper reports new experimental data for forced-convection condensation of ethylene glycol on a set of five single, copper, integral-fin tubes. The five tubes had fin root diameter of 12.7 mm, fin height and thickness of 1.6 mm and 0.25 mm respectively. Fin spacings were 0.25, 0.5, 1.0, 1.5 and 2.0 mm. A plain tube of outside diameter 12.7 mm was also tested. The tests, which were performed at near constant pressure of approximately 15 kPa, covered vapor velocities between 10 and 22 m/s and a wide range of heat fluxes. The best performing tube was that with a fin spacing of 0.5 mm, which had an enhancement ratio (compared to the plain tube at the same vapor-side temperature difference and vapor velocity) of 2.5 at the lowest vapor velocity tested, increasing to 2.7 at the highest. The increase in enhancement ratio with increasing vapor velocity, which is the opposite trend to that found in most earlier experimental studies, was thought to be due to a slight reduction in condensate flooding between the fins due to increased vapor shear.

Switching between Reaction Pathways by an Alcohol Cosolvent Effect: SmI2–Ethylene Glycol vs SmI2–H2O Mediated Synthesis of Uracils

2014 ◽  
Vol 16 (21) ◽  
pp. 5694-5697 ◽  
Author(s):  
Michal Szostak ◽  
Malcolm Spain ◽  
Brice Sautier ◽  
David J. Procter
Keyword(s):  
Ethylene Glycol ◽  
Reaction Pathways

A Reactive Molecular Dynamics Study of Atomistic Mechanisms During Synthesis of MoS2 Layers by Chemical Vapor Deposition

MRS Advances ◽  
2018 ◽  
Vol 3 (6-7) ◽  
pp. 307-311
Author(s):  
Sungwook Hong ◽  
Aravind Krishnamoorthy ◽  
Chunyang Sheng ◽  
Rajiv K. Kalia ◽  
Aiichiro Nakano ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Experimental Studies ◽  
Chemical Vapor ◽  
Reaction Pathways ◽  
Transition Metal Dichalcogenide ◽  
Large Area ◽  
Reactive Molecular Dynamics ◽  
Cvd Synthesis

ABSTRACTTransition metal dichalcogenide (TMDC) monolayers like MoS2 are promising materials for future electronic applications. Large-area monolayer MoS2 samples for these applications are typically synthesized by chemical vapor deposition (CVD) using MoO3 reactants and gas-phase sulfur precursors. Recent experimental studies have greatly improved our understanding of reaction pathways in the CVD growth process. However, atomic mechanisms of sulfidation process remain to be fully elucidated. In this work, we present quantum-mechanically informed and validated reactive molecular dynamics (RMD) simulations for CVD synthesis of MoS2 layers using S2 precursors. Our RMD simulations clarify atomic-level reaction pathways for the sulfidation of MoO3 surfaces by S2, which is a critical reaction step for CVD synthesis of MoS2 layers. These results provide a better understanding of the sulfidation process for the scalable synthesis of defect-free MoS2 and other TMDC materials.

Experimental studies on thermal and rheological properties of Al 2 O 3 –ethylene glycol nanofluid

2018 ◽  
Vol 89 ◽  
pp. 122-130 ◽  
Author(s):  
Krishnakumar T.S. ◽  
Viswanath S.P. ◽  
Sajin Mathew Varghese ◽  
Jose Prakash M
Keyword(s):  
Ethylene Glycol ◽  
Rheological Properties ◽  
Experimental Studies
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