Intrinsic reaction coordinate analysis

Yoshizawa, K., Shiota, Y., Yamabe, T., 1999, Intrinsic Reaction Coordinate Analysis of the Conversion of Methane to Methanol by an Iron-Oxo Species A Study of Crossing Seams of Potential Energy Surfaces , J. Chem. Phys., Ill, 538. 

IRC (intrinsic reaction coordinate analysis), 45 Iridium oxide, amperometry, 650 Iron(II) compounds... 

Intrinsic reaction coordinate following (IRC) analysis by both Bach and coworkers and Du and Houk ° showed that these TSs were connected to both reactant and product without the formation of a radical intermediate consistent with an oxygen insertion into the C—H bond (see inset). Shustov and Rauk ° advocated a bifurcation on the descent... 

In a manner analogous to that described above for nitroethylene, again all quantum mechanical calculations for DADNE were performed with the Gaussian 98 program package [22]. Intrinsic reaction coordinate (IRC) analysis was carried out for each transition state to make sure that it is the transition structure connecting the desired reactants and products. For all structures with an even number of electrons, a restricted (doubly occupied... 

One of the most useful static methods of microscopic chemical kinetics is based on the definition of the reaction path as introduced by Fukui. This method offers information on reactions in terms of the intrinsic reaction coordinate (62,144). A theoretical analysis of the minimum energy path was given in Section III,B. Fukui s definition is equivalent to Eq. (34). 

Energy derivatives are essential for the computation of dynamics properties. There are several dynamics-related methods available in gamess. The intrinsic reaction coordinate (IRC) or minimum energy path (MEP) follows the infinitely damped path from a first-order saddle point (transition state) to the minima connected to that transition state. In addition to providing an analysis of the process by which a chemical reaction occurs (e.g. evolution of geometric structure and wavefunction), the IRC is a common starting point for the study of dynamics. Example are variational transition state theory (VTST [55]) and the modified Shepard interpolation method developed by Collins and co-workers... 

Organic. - Meng et al traced the intrinsic reaction coordinate of the reaction of triplet O with CS2 and analysed its stationary points. The topological analysis of p was employed to investigate the changes of chemical bonds in the reaction process. 

The studies summarized at this point reveal that a static analysis that considers just the electronic properties of the aromatic substrates or the nucleophile as infinitely separated molecules does not give substantial information about the global and local reactivity and their impact in the reaction mechanism. For this reason, more sophisticated analysis has been presented along the intrinsic reaction coordinate that explains in some cases the reactivity of aromatic substrates toward neutral nucleophiles. An additional proposal is presented in this section, which includes the orbital interaction analysis in selected cases between the electrophile and the nucleophile. 

The relative energies obtained for the optimized structures of reactants, transition states, and products provide the reaction energy profile. Transition states are theoretically determined as a saddle point on the potential energy surface, and are confirmed by frequency analysis as well as IRC (intrinsic reaction coordinate) search then kinetics and thermochemistry of a reaction can be obtained. Since direct experimental evidence of elementary reactions is limited, the theoretical infortnation provides insight for improving the current properties of the catalyst. Studies of many catalytically important reactions have been reviewed recently. " ... 

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