SIMULATION OF CONFORMATIONAL DYNAMICS WITH THE MM3 FORCE-FIELD - THE PSEUDOROTATION OF CYCLOPENTANE

A conformational molecular dynamics simulation of cyclopentane has been carried out for 100 ps at room temperature. The conformational interconversion through the pseudorotational pathway was found to be the only conformational motion observable during the simulation. The energetics of the pseudorotational motions match well with the previous predictions of energy minimization studies. Through the energy component analysis, the origin of the lack of a barrier to the pseudorotational pathway was clearly identified. On the kinetic aspect of the pseudorotational motion, an average time cycle of 0.2 ps for pseudorotation was calculated. This time cycle has been estimated on this order of magnitude experimentally. Our study offers a concrete example of the capability within, and accuracy achieved by, the conformational dynamics simulation of organic molecules during the MM3 force field.