Does any compound exist with multiple liquid phases? I've seen some phase diagrams and I found really interesting, how many exotic solid phases of most elements exist on higher pressure and temperature.

But I've seen always only a single liquid phase and also only a single gaseous phase.

The second is understable, but the first not. I think, if there is an unconventional potential energy field between the molecules, maybe it is not impossible.

Does any chemical compounds with multiple liquid phases exist?

If not, why not?



Extension: Well, superfluid helium is one of them. Maybe I don't formulate enough well, but I think on a distinct phase border, like between ice-I and water. As I know, the superfluid helium is a mix of its superfluid and normal fluid phases.
There's no reason why chemical substances with multiple liquid phases shouldn't exist.

In fact there is evidence for the existence of a least a second form of (surprise) liquid water. If you search the Web for liquid-liquid phase transitions you will find more of these, e.g. cerium.