Polonium tetraiodide is a binary inorganic compound of polonium and iodine with the chemical formula . The compound forms volatile black crystals.
1. Action of iodine vapor on polonium metal:
2. Dissolution of polonium dioxide in hydroiodic acid:
The compound forms black crystals that are insoluble in water.
The compound reacts with hydroiodic acid to form hexaiodopolonic acid:
It can be reduced by hydrogen sulfide to yield polonium metal. It decomposes on heating.