Indeed there are. In fact there is an entire class of materials called “ionic liquids”, which are liquid at room temperature. They are not what you would classically think of as a “salt” (ie, a metal halide). read more
With increase in degree of covalency in the bond the melting point of the “ionic compound “ decreases..take the eg of HgI. The compound has a degree of ionicity in its bond. read more
Higher melting point than sodium chloride: around 2,800ºC. This is because its Mg 2+ and O 2-ions have a greater number of charges, so they form stronger ionic bonds than the Na + and Cl-ions in sodium chloride. read more
Ionic compounds typically have much higher melting points than molecular compounds. Ionic compounds are held together by electric attractions between positive and negative ions. These are ionic bonds, and these bonds keep the ions together in a regular 3-d pattern (a crystal lattice) To melt an ionic substance, you have to disrupt these bonds. read more