Cooperative Motion with Solvent Molecules

Next example of the cobaloxime complex has a cyclohexylamine (cha, 7) as an axial base ligand [43]. The crystal structure belongs to the monochnic system and the 

3 Racemizations of Alkyl Groups in Cobaloxime Complex Crysteils 

The racemic crystal was prepared from a benzene solution containing racemic compounds. The crystal has a benzene molecule in an asymmetric unit and the structure is very similar to that produced by photo-irradiation. However, the 1-mce group of the complex takes a complicated disordered form. 

The reaction cavities for the 1-mce groups of A and B before photo-irradiation are drawn as shown in Fig. 3.31. The R configuration of the A mce group is well 

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An important exception are atomic simulations of proteins in explicit solvent, where individual particles (e,g, water molecules) represent the solvent Monte Carlo updates of the system would too frequently collide with solvent particles which causes unacceptably high rejection rates of trial moves. In this case, the cooperative many-body motion is more efficiently simulated by integrating the equations of motion of each particle step by step. It can even be most efficient to combine Monte Carlo and nwlecular dynamics. The most prominent hybrid method is replica-exchange molecular dynamics (REMD), where Langevin simulations ran in different threads at various temperatures and the replicas are exchanged after some time steps with the exchange transition probability (4.92), which effectively is a Monte Carlo step. 

The reaction of an amorphous polymer with a solvent is dependent upon diffusion of the attacking reactant. If the polymer is at a temperature above its Tg there is a constant cooperative segmental motion that favors diffusion from hole to hole in the polymer mass wherein hole formation in a polymer above its Tg is related to the relative mobility of the diffusing molecules. The rate of diffusion is dependent on the temperature, the molecular size, and the extent of the compatibility of the corrosive molecules with those of the polymer (36). 

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