Ethane Rotation About the Carbon-Carbon Single Bond

Simulated ultra slow motion low temperature molecular dynamics animation of the rotation about the carbon-carbon single bond of ethane. Shown using a space filling model, with vibrational motion suppressed. Usually the rotational motion is seen to reverse as hydrogens on the adjacent carbons approach each other, owing to the energy barrier to rotation. Here the molecule has sufficient energy so that the hydrogens pass by each other, overcoming the barrier, about 25% of the time. In real time at room temperature the rotation would be incredibly faster than shown here, passing through all conformations on the femtosecond time scale. Excerpted (without audio) from the full interactive unit "Ethane Rotation" in the collection of Lecture Projection/Tutorial Graphics at
http://faculty.washington.edu/dwoodma...