Methyl group rotation enones

Computer Simulation of Pyramidalization. This hypothesis was tested by computer simulation of the pyramidalization at either Ca or Co of a single molecule surrounded by its stationary lattice neighbors. Using the X-ray crystal structure-derived coordinates of enones J arUl. as a starting point, the methyl groups attached to C and Co were rotated downwards by intervals of 11°, 22°, 33°,... 

Figure 6. Hydrogen—hydrogen contacts versus angle of rotation for the pyramidalized methyl group of enone Of the nine...

Case (B) conesponds to the diffusion-controlled reactions of small molecules with functional groups on polymer side diains. Because the local mode of relaxation of a polymer main chain ( -dispersion) and the rotation of a polymer side diain or phenyl group in the main chain (y-dispersicm) occur below T, the reactions controlled by the side chain local motion begin at temperature correspondmg to the onset of rotational motion and show breals at and T. Quenching or hydrogen abstraction of the benzo d)enone triplet in pofy(methyl methacrylate) may be explained in terms of this idea. 

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