Reactions, optimizing trajectories

Another way of visualizing the optimal trajectory for the exothermic reversible reaction is to consider isothermal reaction rates at increasing temperatures. At T the equilibrium conversion is high but the rate is low, at T2 the rate is higher but the equihbrium conversion is lower, at the rate has increased further and the equihbrium conversion is even lower, and at a high temperature T4 the initial rate is very high but the equihbririm conversion is very low. 

The reaction coordinate ----, a more optimal trajectory for tunneling. The arrows show the... 

Common to these methods is that the reaction kinetic model with few exceptions is perceived as the calculating basis for finding the optimal trajectories for control parameters as... 

If the heat of reaction increases, the optimal trajectory converges faster toward the center line as shown in Fig. 2G. The reason is the reactor inlet temperature will become lower for system with a larger heat of reaction (this can be seen from the overall energy as will be... 

The optimal trajectory can be computed directly from Eq.(8) and this facilitates the investigation of chemical reactions with different kinetics parameters and vapour liquid equilibrium. More importantly, the trajectories obtained provided insight to possible tradeoffs between design and control for different bimolecular reactions. 

Reactions of this type are numerous and important for biological systems [164-166]. An ion-molecular reaction of mixed sulfur dihalogenide with the fluoride ion was studied by the CNDO/2 method in order to determine the optimal trajectory for an approach of the nucleophile to the dicoordinate sulfur atom [167] ... 

Optimizing trajectory of batch, semibatch, and continuous reactions By controlling reaction processes to follow the optimum path to desired product properties, time is minimized, similar to following an optimized road route using a GPS. 

It seems that the repulsive steric interactions play a more dominant role in regioselectivity of aryne reactions than is sometimes realized. In fact, it has been argued that in nucleophilic addition to arynes, the transition state is reached early, while the incipient bond is still very much extended. Consequently, steric effects were considered not to be of great importance.80 81 It should, however, be noted that the dehydro bond orbitals are so oriented that the optimal approach trajectory for the nucleophile lies in the... 

Most of other trajectories obtained in this study exhibited intermediate characters between trajectories (a) and (b). An important message was that the chemical reaction does not always proceed through the lowest energy pathway with optimal solvation. In conclusion, the simulations for the first time illustrated how the atoms in reacting molecules behave in solution at the molecular level, which was made possible by using full QM simulations with the recently developed FMO-MD methodology. 

Roca and coworkers next examined the potential coupling between the reactants and the COMT enzyme. Employing the same computational methods as in the previous paper, they carried out a 600-ps MD trajectory with the system constrained to remain near the TS. Using the geometry at every 50 ps, they optimized true TS structures and determined their transition vectors. An average of these vectors showed a near complete dominance of motion that one associates with the Sn2 reaction and little motion in the rest of the QM or MM regions. 

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