Preparation of cholesteryl benzoate

We prepare a sample of cholesteryl benzoate in this experiment which forms an interesting liquid crystal phase on heating. The molecule is chiral. This is a standard preparation for an organic solid. The chemical reaction is first carried out, followed by purification of the solid using recrystallization and suction filtration. You may notice a small spillage in the suction filtration in the video - this is not the way to do it! However, it is a subtle balance between pouring too fast and causing a spill, and pouring too slow and leaving the solid stuck to the flask.

The video shows the clear melt being cooled down in real time. A purple glow spreads through the liquid as it turns into a cloudy liquid crystal phase. A further purple glow spreads again as the liquid crystal phase becomes solid.

Video - the preparation of cholesteryl benzoate