The transesterification reaction, and in particular the methanolysis of ethyl acetate with sulfuric acid as catalyst, is used as a model reaction to study the acid-catalyzed nucleophilic addition to a carbonyl group. Continuum solvation methods (SMD and IEF-PCM) and the MPWB1K functional are used. The reaction mechanism is studied in methanol and in acetonitrile as solvents. Our results indicat...

Efficient sampling in both configuration and trajectory spaces, combined with mechanism analyses via data mining, allows a systematic investigation of the thermodynamics, kinetics, and molecular-detailed dynamics of chemical reactions in solution. Through a Bayesian learning algorithm, the reaction coordinate(s) of a (retro-)Claisen rearrangement in bulk water was variationally optimized. The b...

The kinetics of toluene hydrogenation over Ni-supported catalysts with various supports was investigated under the wide range of conditions as 130 to 210 °C reaction temperature, 2.6×10-5 to 5.9×10-5 atm partial pressure of hydrogen and 1.4×10-9 to 3.7×10-8 atm partial pressure of toluene. For more study, two kinetics models were also selected and studied to describe the kinetics of this proces...

Complex molecules often have many structures (conformations) of the reactants and the transition states, and these structures may be connected by coupled-mode torsions and pseudorotations; some but not all structures may have hydrogen bonds in the transition state or reagents. A quantitative theory of the reaction rates of complex molecules must take account of these structures, their coupled-m...

We analyze the dynamics of a reaction propagating along a two-dimensional medium of nonuniform composition. We consider the context of a self-sustaining reaction front that converts a monomer-initiator mixture into an inhomogeneous polymeric material. We model the system with one-step effective kinetics, assuming large activation energy. Using asymptotic methods, we find the analytical expressi...

A theoretical formulation is developed for the activated kinetics when some subset of nuclear modes of the thermal bath is slower than the reaction and ergodicity of the thermal bath is not maintained. Nonergodic free energy profiles along the reaction coordinate are constructed by using restricted canonical ensembles with the phase space available to the system found by solving a self-consiste...

The kinetics of the elementary reactions involved in the low-temperature combustion of alkanes are reviewed. The reactions are centred on the alkyl radical and its decomposition, recombination and reactions with 0,. A combination of theory, modelling and direct measurements, using especially laser flash photolysis, have played key roles in the characterisation of all three reaction types. A rem...

This paper concerns the long-term behavior of population systems, and in particular of chemical reaction systems, modeled by deterministic mass-action kinetics. We approach two important open problems in the field of chemical reaction network theory: the Persistence Conjecture and the Global Attractor Conjecture. We study the persistence of a large class of networks called lower-endotactic and,...