Cyclopentane How to manipulate JSmol structures The flap carbon of cyclopentane is blue. Superimpose the blue carbon and an adjacent red carbon. Note that C-H bond eclipsing is reduced between these carbon atoms. Superimpose a red carbon next to the blue carbon with its other red neighbor. Note that the eclipsing interaction is reduced. View down the axis of the C-C bond that is across from the blue carbon. Note the eclipsed C-H bonds. All the red carbons lie in a plane. Convince yourself. Cyclopentane is not static. Each of the five atoms gets a turn to be "blue".