Femtosecond Nucleophilic Substitution Reaction Dynamics

Zhong, Dongping; Ahmad, Saleem; Cheng, Po‐Yuan; Zewail, Ahmed H.

doi:10.1021/ja963879k

Cited by 11 publications

(11 citation statements)

References 27 publications

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“…The quotas of stock solution were diluted to different initial concentrations and placed in a series of stainless steel hydrothermal microreactors at constant temperature for 1 h. The reaction was initiated by injecting appropriate saturated trimethylamine solution into the hydrothermal microreactors with a gas tight syringe, yielding initial concentrations of C 10 H 21 ClCHCOO -HN ? (CH 3 ) 3 and trimethylamine in the range from 0.02 to 0.1 mol/L. Then the hydrothermal microreactor was sealed and incubated in a water bath at the appropriate temperature (±0.5°C) with continuous gentle stirring.…”

Section: Kinetic Measurementsmentioning

confidence: 99%

See 1 more Smart Citation

A Kinetics and Mechanism Investigation of the Nucleophilic Substitution Reaction of α‐Chlorododecyl Carboxylate with Trimethylamine

Wang

Zhang

Fang

et al. 2010

J Surfact & Detergents

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A nucleophilic substitution reaction was developed to synthesize the zwitterionic surfactant using a renewable natural fatty acid rather than a petroleum derivative as the raw material. The kinetics and mechanism of the nucleophilic substitution reaction of trimethylamine a-chlorododecyl carboxylate with trimethylamine were investigated in protic and dipolar aprotic solvents including water, ethanol and N, N-dimethyl formamide. The rate equations were derived using initial rates and the activation parameters in different solvents were determined empirically and compared with each other to obtain important information about the reaction mechanism. The overall second-order reaction number and the negative activation entropy supported a bimolecular nucleophilic substitution (S N 2) mechanism, combined with the pseudo-first-order kinetics for each reactant. The experimental results also showed that the reaction reactivity diminishes with the decrease in polarity of protic solvents. The typical dipolar aprotic solvent dimethyl formamide distinctively promoted the reaction in. This fact was successfully explained by the solvation rule for S N 2 reactions.

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Section: Kinetic Measurementsmentioning

confidence: 99%

“…The nucleophilic substitution reaction is among the most popular approaches in organic chemistry [1][2][3][4][5][6][7]. Recently our group has developed a nucleophilic substitution pathway to synthesize the zwitterionic surfactant named a-long alkylbetaine (Scheme 1) [8].…”

Section: Introductionmentioning

confidence: 99%

A Kinetics and Mechanism Investigation of the Nucleophilic Substitution Reaction of α‐Chlorododecyl Carboxylate with Trimethylamine

Wang

Zhang

Fang

et al. 2010

J Surfact & Detergents

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“…A major recent experimental advance has been the ability to use time-resolved pump-probe laser methods to study chemical processes occurring on a time scale of femtoseconds (10 Ϫ15 s) (37). Reactive scattering theory has also been developed to help understand the results of such experiments that can probe directly the transition states of chemical reactions.…”

Section: Time-resolved Dynamicsmentioning

confidence: 99%

Quantum Theory of Chemical Reaction Dynamics

Clary

1998

Science

149

107

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It is now possible to use rigorous quantum scattering theory to perform accurate calculations on the detailed state-to-state dynamics of chemical reactions in the gas phase. Calculations on simple reactions, such as H + D2 --> HD + D and F + H2 --> HF + H, compete with experiment in their accuracy. Recent advances in theory promise to extend such accurate predictions to more complicated reactions, such as OH + H2 --> H2O + H, and even to reactions of molecules on solid surfaces. New experimental techniques for probing reaction transition states, such as negative-ion photodetachment spectroscopy and pump-probe femtosecond spectroscopy, are stimulating the development of new theories.

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“…[17][18][19][20][21][22][23][24][25] Recently, renewed interest has been devoted to aromatic nucleophilic substitution reactions effected by halide ions in the gas phase, and the dynamics have been examined with femtosecond resolution on an overall neutral system. [26] In an anionic system, the fast reaction of fluoride ion with nitrobenzene is found to proceed via an ipso complex, which represents the reaction transition state rather than a reaction intermediate. [27] In order for an anionic s complex to become a long-lived species in the gas phase rather than a transient, the ortho/para positions with respect to the tetraAbstract: Anion-p interactions between a p-acidic aromatic system and an anion are gaining increasing recognition in chemistry and biology.…”

Section: Introductionmentioning

confidence: 99%

Molecular Complexes of Simple Anions with Electron‐Deficient Arenes: Spectroscopic Evidence for Two Types of Structural Motifs for Anion–Arene Interactions

Chiavarino

Crestoni

Fornarini

et al. 2009

Chemistry A European J

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Anion-pi interactions between a pi-acidic aromatic system and an anion are gaining increasing recognition in chemistry and biology. Herein, the binding features of an electron-deficient aromatic system (1,3,5-trinitrobenzene (TNB)) and selected anions (OH-, Br-, and I-) are examined in the gas phase by using the combined information derived from collision-induced dissociation experiments at variable energy, infrared multiple-photon dissociation spectroscopy, and quantum chemical calculations. We provide spectroscopic evidence for two different structural motifs of anion-arene complexes depending on the nature of the anion. The TNB-OR- complexes (R=H, or alkyl groups which were studied earlier) adopt an anionic sigma-complex structure whereby RO- attacks the aromatic ring with covalent bond formation, and develops a tetrahedral ring carbon bound to H and OR. The halide complexes rather conform to a structure in which the TNB moiety is hardly altered, and the halogen is placed on an unsubstituted carbon atom over the periphery of the ring at a C-X distance that is appreciably longer than a typical covalent bond length. The ensuing structural motif, previously characterized in the solid state and named weak sigma interaction, is now confirmed by an IR spectroscopic assay in the gas phase, in which the sampled species are unperturbed by crystal packing or solvation effects.

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Femtosecond Nucleophilic Substitution Reaction Dynamics

Cited by 11 publications

References 27 publications

A Kinetics and Mechanism Investigation of the Nucleophilic Substitution Reaction of α‐Chlorododecyl Carboxylate with Trimethylamine

A Kinetics and Mechanism Investigation of the Nucleophilic Substitution Reaction of α‐Chlorododecyl Carboxylate with Trimethylamine

Quantum Theory of Chemical Reaction Dynamics

Molecular Complexes of Simple Anions with Electron‐Deficient Arenes: Spectroscopic Evidence for Two Types of Structural Motifs for Anion–Arene Interactions

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