Cerium Iodide

Chemical Properties

white or reddish white crystal(s) [MER06]

Uses

Cerium(III) iodide is used as a pharmaceutical intermediate.

Reactivity Profile

Organocerium reagents prepared from cerium triiodide and organolithiums have reduced basicity and possess enhanced nucleophilicity toward the carbonyl group; promotes aldol reaction between α-halo ketones and aldehydes; in combination with LiAlH4 is a selective 1,2-reducing agent.

Synthesis

Pure CeI3 (Cerium (III) iodide) is prepared by reacting metallic cerium with iodine or mercury(II) iodide at high temperature.Another method is to dissolve CeO2 in an aqueous HI solution, adding 12 moles of NH4I per mole of CeO2 and evaporating the mixture to dryness. The mixture is heated in vacuo at 300- 350 °C to leave pure CeI3. CeI3 is prepared in situ by reacting powdered cerium with iodine in THF[1-4].

Precautions

Cerium (III) iodide is extremely hygroscopic and turns brown when exposed to air owing to the liberation of iodine. This reagent should be stored under nitrogen and handled in a glove bag.

References

1. Jantsch, G.; Grubitsch, H.; Hoffmann, F.; Alber, H. ZC 1929, 185, 49.
2. Asprey, L. B.; Keenan, T. K.; Kruse, F. H. IC 1964, 3, 1137.
3. Taylor, M. D. CRV 1962, 62, 503.
4. Imamoto, T.; Kusumoto, T.; Tawarayama, Y.; Sugiura, Y.; Mita, T.; Hatanaka, Y.; Yokoyama, M. JOC 1984, 49, 3904.