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.