Reaction dynamics through kinetic transition states.
نویسندگان
چکیده
The transformation of a system from one state to another is often mediated by a bottleneck in the system's phase space. In chemistry, these bottlenecks are known as transition states through which the system has to pass in order to evolve from reactants to products. The chemical reactions are usually associated with configurational changes where the reactants and products states correspond, e.g., to two different isomers or the undissociated and dissociated state of a molecule or cluster. In this Letter, we report on a new type of bottleneck which mediates kinetic rather than configurational changes. The phase space structures associated with such kinetic transition states and their dynamical implications are discussed for the rotational vibrational motion of a triatomic molecule. An outline of more general related phase space structures with important dynamical implications is given.
منابع مشابه
Quantum Mechanical Approach for the Catalytic Mechanism of Dinuclear Zinc Metallo-β-lactamase by Penicillin and Cephalexin: Kinetic and Thermodynamic Points of View
Metallo-β-lactamases (MβL) catalyzing the hydrolytic cleavage of the four-membered β-lactam ring in broad spectrum of antibiotics and therefore inactivating the drug; However, the mechanism of these enzymes is still not well understood. Electronic structure and electronic energy of metallo-β-lactamase active center, two inhibitors of this enzyme including penicillin and cephalexin, and differen...
متن کاملReaction Path Optimization and Sampling Methods and Their Applications for Rare Events
Reaction mechanisms are an important tool for chemists in the determination of thermodynamic and kinetic properties of chemical reactions.(Hänggi & Borkovec 1990; Heidrich 1995; March 1992; Tolman 1925) The mechanisms are integral in the understanding of detailed molecular or chemical transitions from one equilibrium state (reactant) to another equilibrium state (product). In computational chem...
متن کاملIsotope Effects, Dynamic Matching, and Solvent Dynamics in a Wittig Reaction. Betaines as Bypassed Intermediates
The mechanism of the Wittig reaction of anisaldehyde with a stabilized ylide was studied by a combination of (13)C kinetic isotope effects, conventional calculations, and molecular dynamics calculations in a cluster of 53 THF molecules. The isotope effects support a cycloaddition mechanism involving two sequential transition states associated with separate C-C and P-O bond formations. However, ...
متن کاملInfluence of water and enzyme SpnF on the dynamics and energetics of the ambimodal [6+4]/[4+2] cycloaddition.
SpnF is the first monofunctional Diels-Alder/[6+4]-ase that catalyzes a reaction leading to both Diels-Alder and [6+4] adducts through a single transition state. The environment-perturbed transition-state sampling method has been developed to calculate free energies, kinetic isotope effects, and quasi-classical reaction trajectories of enzyme-catalyzed reactions and the uncatalyzed reaction in ...
متن کاملReaction dynamics during the testing of polymerization catalyst
The olefins polymerization process in a slurry reactor is discussed. The reaction rate dynamics was analyzed and the contributions of feed flow, gas-liquid mass transfer, polymerization reaction, and catalyst deactivation were estimated. The propylene solubility in a solvent mixture “heptane” was calculated using Soave-Redlich-Kwong equation of state. These data were then approximated by Henry-...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Physical review letters
دوره 110 23 شماره
صفحات -
تاریخ انتشار 2013