Bismuth(III) iodide

Bismuth(III) iodide forms upon heating an intimate mixture of iodine and bismuth powder: :2 Bi + 3 I2 → 2 BiI3 BiI3 can also be made by the reaction of bismuth oxide with aqueous hydroiodic acid: :Bi2O3(s) + 6 HI(aq) → 2 BiI3(s) + 3 H2O(l) ==Reactions==

Since bismuth(III) iodide is insoluble in water, an aqueous solution can be tested for the presence of Bi3+ ions by adding a source of iodide such as potassium iodide. A black precipitate of bismuth(III) iodide indicates a positive test. Bismuth(III) iodide forms pentaiodobismuth(III) anions when heated with halide donors: :2 NaI + BiI3 → Na2[BiI5] Bismuth(III) iodide catalyzes the Mukaiyama aldol reaction. Bi(III) is also used in a Barbier type allylation of carbonyl compounds in combination with a reducing agent such as zinc or magnesium. ==References==