Imaging the Effects of Bend-Excitation in the F + CD4(vb=0,1) → DF(v) + CD3(v2=1,2) Reactions

Wang, Fengyan; Liu, Kopin

doi:10.1021/jp4014866

Cited by 26 publications

(22 citation statements)

References 62 publications

(141 reference statements)

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“…The effects of exciting various vibrational modes of the methane reactant have been examined by Liu and coworkers. [51][52][53][54] Interestingly, the excitation of the C-H stretching (v 1 ) mode in CHD 3 was found at low collision energies to inhibit its reaction with F, leading to the HF + CD 3 products. 51 This surprising effect was speculated as the result of the stereodynamical forces exerting on the approaching reactants by the pre-reaction van der Waals wells.…”

Section: Resultsmentioning

confidence: 99%

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Mode Specificity, Bond Selectivity, and Product Energy Disposal in X + CH₄/CHD₃ (X=H, F, O(³P), Cl, and OH) Hydrogen Abstraction Reactions: Perspective from Sudden Vector Projection Model

Jiang

Guo

2014

J Chinese Chemical Soc

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Reactions between methane and various radicals have become the workhorse in our understanding of mode specificity and bond selectivity in bimolecular reactions. In this work, the recently proposed Sudden Vector Projection (SVP) model is used to gain insight into the existing experimental and theoretical data on these reactions. The SVP model attributes mode specificity and bond selectivity to the coupling of reactant modes/bonds with the reaction coordinate at the transition state. In the sudden limit, the strength of the coupling can be simply computed by projecting the corresponding reactant normal mode vector onto that of the imaginary frequency mode at the saddle point. In addition, the SVP model can be used to predict energy disposal in the products, thanks to microscopic reversibility. It is shown that most of the mode-specific and bond-selective chemistry in X + CH 4 /CHD 3 (X=H, F, O( 3 P), Cl, and OH) reactions can be reasonably understood with this simple model.

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Section: Resultsmentioning

confidence: 99%

“…In addition, both experimental and QCT results suggested that the bending excitation enhances the reaction at low collision energies, but inhibits the reaction at high collision energies. [53][54]56 However, it was argued that the reaction is mediated by resonances at this energy range.…”

Section: Resultsmentioning

confidence: 99%

Mode Specificity, Bond Selectivity, and Product Energy Disposal in X + CH₄/CHD₃ (X=H, F, O(³P), Cl, and OH) Hydrogen Abstraction Reactions: Perspective from Sudden Vector Projection Model

Jiang

Guo

2014

J Chinese Chemical Soc

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“…Obviously, it cannot account for the collisional energy dependency of the reactant mode (vibration vs. translation) preference and the translational propensity almost universally found at lower E c . 21,25,27,76,77,84,85 Then, is the vibrational-induced steric effect relevant to Polanyi's rules and the mode-/bond-selectivity? The energy requirement in Polanyi's rules deciphers the relative efficacies of different forms of reactants' energy (vibration or translation) to surmount the reaction barrier.…”

Section: Concluding Remarks and Outlookmentioning

confidence: 99%

Perspective: Vibrational-induced steric effects in bimolecular reactions

Liu

2015

The Journal of Chemical Physics

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The concept of preferred collision geometry in a bimolecular reaction is at the heart of reaction dynamics. Exemplified by a series of crossed molecular beam studies on the reactions of a C-H stretch-excited CHD3(v1 = 1) with F, Cl, and O((3)P) atoms, two types of steric control of chemical reactivity will be highlighted. A passive control is governed in a reaction with strong anisotropic entry valley that can significantly steer the incoming trajectories. This disorientation effect is illustrated by the F and O((3)P) + CHD3(v1 = 1) reactions. In the former case, the long-range anisotropic interaction acts like an optical "negative" lens by deflecting the trajectories away from the favored transition-state geometry, and thus inhibiting the bond rupture of the stretch-excited CHD3. On the contrary, the interaction between O((3)P) and CHD3(v1 = 1) behaves as a "positive" lens by funneling the large impact-parameter collisions into the cone of acceptance, and thereby enhances the reactivity. As for reactions with relatively weak anisotropic interactions in the entry valley, an active control can be performed by exploiting the polarization property of the infrared excitation laser to polarize the reactants in space, as demonstrated in the reaction of Cl with a pre-aligned CHD3(v1 = 1) reactant. A simpler case, the end-on versus side-on collisions, will be elucidated for demonstrating a means to disentangle the impact-parameter averaging. A few general remarks about some closely related issues, such as mode-, bond-selectivity, and Polanyi's rules, are made.

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“…In literature it can be observed that many adsorption isotherms, applied for various systems, were tested on MIP systems also. Langmuir, bi‐Langmuir, tri‐Langmuir, Freundlich, Freundlich‐Langmuir, Dubinin‐Radushkevic, Temkin, Halsey, Jovanovic, bi‐Jovanovic, Freundlich‐Jovanovic, and Harkins‐Jura isotherms were used to express the adsorption in MIPs , while Lagergren first order, pseudo second order, and Elovich models were used to evaluate the kinetics in these selective adsorbents .…”

Section: Introductionmentioning

confidence: 99%

Equilibrium and kinetic isotherms and parameters for molecularly imprinted with sclareol poly(acrylonitrile‐co‐acrylic acid) matrix

Dima

2014

Polymer Engineering & Sci

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The present work continues the previous studies concerning the synthesis and characterization of molecularly imprinted polymers (MIPs) with sclareol as template and three poly(acrylonitrile‐co‐acrylic acid) (AN:AA) copolymers with different ratios between monomers as matrices. The previous studies of rheology, elemental analysis, infrared spectroscopy, size exclusion chromatography, thermogravimetry, differential scanning calorimetry, batch rebinding tests, and Scatchard analysis, which confirmed the molecular imprinting, are being completed with the current equilibrium and kinetic adsorption studies. For this purpose, eight adsorption isotherms and three kinetic adsorption models were applied to six sets of experimental data obtained after three sclareol‐imprinted adsorbents (MIPs) and three nonimprinted adsorbents (NIPs) were submitted to batch adsorption experiments. After ordering the adsorption models according to the “minimum sum of normalized errors (SNE)” criteria, it was concluded that the adsorption in sclareol imprinted AN:AA copolymers is characterized by low surface coverage, takes place on heterogeneous binding sites and is reversible, while for NIPs the results suggest a difficult adsorption and/or easiness of template extraction, and that NIPs have homogeneous, but nonimprinted micropores. For the kinetic experiments, the minimum SNE for MIPs points to the first order kinetic model, fact that suggests a physical adsorption of template molecules on the imprinted sites. POLYM. ENG. SCI., 55:1152–1162, 2015. © 2014 Society of Plastics Engineers

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Imaging the Effects of Bend-Excitation in the F + CD₄(v_b=0,1) → DF(v) + CD₃(v₂=1,2) Reactions

Cited by 26 publications

References 62 publications

Mode Specificity, Bond Selectivity, and Product Energy Disposal in X + CH₄/CHD₃ (X=H, F, O(³P), Cl, and OH) Hydrogen Abstraction Reactions: Perspective from Sudden Vector Projection Model

Mode Specificity, Bond Selectivity, and Product Energy Disposal in X + CH₄/CHD₃ (X=H, F, O(³P), Cl, and OH) Hydrogen Abstraction Reactions: Perspective from Sudden Vector Projection Model

Perspective: Vibrational-induced steric effects in bimolecular reactions

Equilibrium and kinetic isotherms and parameters for molecularly imprinted with sclareol poly(acrylonitrile‐co‐acrylic acid) matrix

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Imaging the Effects of Bend-Excitation in the F + CD4(vb=0,1) → DF(v) + CD3(v2=1,2) Reactions

Cited by 26 publications

References 62 publications

Mode Specificity, Bond Selectivity, and Product Energy Disposal in X + CH4/CHD3 (X=H, F, O(3P), Cl, and OH) Hydrogen Abstraction Reactions: Perspective from Sudden Vector Projection Model

Mode Specificity, Bond Selectivity, and Product Energy Disposal in X + CH4/CHD3 (X=H, F, O(3P), Cl, and OH) Hydrogen Abstraction Reactions: Perspective from Sudden Vector Projection Model

Perspective: Vibrational-induced steric effects in bimolecular reactions

Equilibrium and kinetic isotherms and parameters for molecularly imprinted with sclareol poly(acrylonitrile‐co‐acrylic acid) matrix

Contact Info

Product

Resources

About

Imaging the Effects of Bend-Excitation in the F + CD₄(v_b=0,1) → DF(v) + CD₃(v₂=1,2) Reactions

Mode Specificity, Bond Selectivity, and Product Energy Disposal in X + CH₄/CHD₃ (X=H, F, O(³P), Cl, and OH) Hydrogen Abstraction Reactions: Perspective from Sudden Vector Projection Model

Mode Specificity, Bond Selectivity, and Product Energy Disposal in X + CH₄/CHD₃ (X=H, F, O(³P), Cl, and OH) Hydrogen Abstraction Reactions: Perspective from Sudden Vector Projection Model