Using a combination of X-ray and neutron scattering techniques, the NIST/UC group determined that cubane molecules stack differently at different temperatures. Heated to 121 degrees C in a specially designed furnace, the researchers found that the cube-shaped molecules do not stack on top of one another at neat 90 degree angles. Instead the molecules are rotated in space with respect to adjacent molecules just enough to flatten the stack into a rhomboid shape. This unexpected result may affect how chemists design steps for processing cubane.

The graphic above shows a model of a cubane molecule superimposed on a chart based on calculations that predict cubane’s preferred stacking geometries at different temperatures. The group’s experimental results confirmed these modeling predictions.