Related Experiment Video
Updated: Apr 25, 2026
09:45
Accessing Valuable Ligand Supports for Transition Metals: A Modified, Intermediate Scale Preparation of 1,2,3,4,5-Pentamethylcyclopentadiene
Published on: March 20, 2017
9.6K
Rotational mode specificity in the Cl + CHD3 → HCl + CD3 reaction
Rui Liu1, Fengyan Wang2, Bin Jiang3
1Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Center for Magnetic Resonance, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China.
The Journal of Chemical Physics
|August 24, 2014
Summary
Exciting rotational modes in vibrationally excited deuterated methane (CHD3) significantly enhances its reactivity in reactions with chlorine (Cl). This mode-specific enhancement is attributed to changes in the reaction
Area of Science:
- Chemical kinetics
- Molecular dynamics
- Quantum chemistry
Background:
- The reaction between chlorine atoms and methane molecules is a fundamental process in atmospheric chemistry and combustion.
- Understanding mode-specific reactivity in chemical reactions is crucial for controlling reaction outcomes.
- Vibrational and rotational excitations can significantly influence chemical reaction rates and pathways.
Purpose of the Study:
- To investigate the effect of rotational excitation on the reactivity of vibrationally excited deuterated methane (CHD3) in the reaction with chlorine atoms (Cl).
- To elucidate the underlying dynamical mechanisms responsible for the observed mode-specific reactivity enhancement.
- To compare theoretical predictions with experimental observations for the Cl + CHD3 reaction.
Main Methods:
- Utilizing a reduced-dimensional quantum dynamical model to simulate the reaction.
- Employing the conventional quasi-classical trajectory method for dynamical studies.
- Analyzing reaction mechanisms using a Franck-Condon model and trajectory inspection.
Main Results:
- Rotational excitation of CHD3 (v1 = 1, JK) enhances the Cl + CHD3 → HCl + CD3 reaction rate by up to a factor of two compared to rotationless reactants.
- The quantum dynamical model and quasi-classical trajectory simulations qualitatively reproduced the experimental enhancements.
- Higher reactivity for J states of CHD3 with K = 0 is linked to an enlarged "cone of acceptance" for the reaction.
- Less pronounced enhancement for higher J = K states is attributed to less effective C-H bond rotation in opening the cone of acceptance.
Conclusions:
- Rotational modes play a significant role in controlling the reactivity of the Cl + CHD3 reaction.
- The "cone of acceptance" mechanism, influenced by rotational excitation, is key to understanding mode-specific reactivity.
- Theoretical models are valuable tools for explaining and predicting mode-specific effects in chemical reactions.
More Related Videos
Related Concept Videos
01:33Radical Halogenation: Stereochemistry
3.6K
Stereochemistry is the study of the different spatial arrangements of atoms in a given molecule. The stereochemistry of radical halogenations can be understood from three different situations:
Halogenation to form a new chiral center:
Halogenation to form a new chiral center:
3.6K
02:05Prochirality
4.0K
The concept of prochirality leads to the nomenclature of the individual faces of a molecule and plays a crucial role in the enantioselective reaction. It is a concept where two or more achiral molecules react to produce chiral products. A typical process is the reaction of an achiral ketone to generate a chiral alcohol. Here, the achiral reactant reacts with an achiral reducing agent, sodium borohydride, to generate an equimolar mixture of the chiral enantiomers of the product. For example, an...
4.0K
![[3,3] Sigmatropic Rearrangement of Allyl Vinyl Ethers: Claisen Rearrangement](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2Ffiles%2Fmedia%2Fscience-education%2Fscience-education-thumbs%2F13097.jpg&w=3840&q=75)
01:24[3,3] Sigmatropic Rearrangement of Allyl Vinyl Ethers: Claisen Rearrangement
1.9K
The Claisen rearrangement is a [3,3] sigmatropic rearrangement of allyl vinyl ethers to unsaturated carbonyl compounds. The rearrangement is a concerted pericyclic reaction proceeding via a chair-like transition state.
1.9K
02:17Regioselectivity of Electrophilic Additions to Alkenes: Markovnikov's Rule
14.0K
If a set of reactants can yield multiple constitutional isomers, but one of the isomers is obtained as the major product, the reaction is said to be regioselective. In such reactions, bond formation or breaking is favored at one reaction site over others.
The hydrohalogenation of an unsymmetrical alkene can yield two haloalkane products, depending on which vinylic carbon takes up the halogen. However, one product usually predominates, where hydrogen adds to the vinylic carbon bearing the...
The hydrohalogenation of an unsymmetrical alkene can yield two haloalkane products, depending on which vinylic carbon takes up the halogen. However, one product usually predominates, where hydrogen adds to the vinylic carbon bearing the...
14.0K
01:17Thermal Electrocyclic Reactions: Stereochemistry
1.6K
The stereochemistry of electrocyclic reactions is strongly influenced by the orbital symmetry of the polyene HOMO. Under thermal conditions, the reaction proceeds via the ground-state HOMO.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
1.6K
02:46Halogenation of Alkenes
16.8K
Halogenation is the addition of chlorine or bromine across the double bond in an alkene to yield a vicinal dihalide. The reaction occurs in the presence of inert and non-nucleophilic solvents, such as methylene chloride, chloroform, or carbon tetrachloride.
Consider the bromination of cyclopentene. Molecular bromine is polarized in the proximity of the π electrons of cyclopentene. An electrophilic bromine atom adds across the double bond, forming a cyclic bromonium ion intermediate.
Consider the bromination of cyclopentene. Molecular bromine is polarized in the proximity of the π electrons of cyclopentene. An electrophilic bromine atom adds across the double bond, forming a cyclic bromonium ion intermediate.
16.8K