What Is The Color Of Gold Iodide?

Gold iodide (AuI3) is a yellow crystalline solid with a melting point of 168°C. It has a structure similar to that of aluminum chloride and consists of Au+3 cations and I- anions. The yellow color of gold iodide is due to the absorption of light in the blue-green region of the spectrum, which results from the interaction between the d-orbitals of the gold atoms and the surrounding iodide ions. Gold iodide is sparingly soluble in water and insoluble in most organic solvents.