What Is Zinc Iodide?
Zinc iodide, with the formula ZnI2, is a deliquescent compound existing in both anhydrous and dihydrate forms.
Uses of Zinc Iodide
Its applications range from radiation shielding and as a component in zinc iodide starch indicators to a reagent in the Simmons-Smith reaction, a disinfectant in dentistry, and electronic material manufacturing. Zinc iodide starch indicator turns blue in the presence of oxidants, aiding in their detection. The Simmons-Smith reaction utilizes zinc iodide to cyclopropanate olefins, valuable in synthesizing cyclopropane-containing substances.
Properties of Zinc Iodide
Zinc iodide is a white to yellowish-brown powder with a formula weight of 319.218. It melts at 446°C and decomposes upon boiling at 624°C. Highly soluble in water and ethanol, it should be stored away from light and moisture due to its deliquescent nature.
Types of Zinc Iodide
Available as a reagent and in industrial grades, zinc iodide is offered in various volumes for lab use and in larger quantities for electronic applications. Zinc iodide starch solution is also available for specific analytical uses.
Other Information on Zinc Iodide
1. Synthesis of Zinc Iodide
Production methods include reacting metallic zinc with iodine under heat or dissolving zinc in aqueous iodide solutions. Laboratory synthesis often involves a reaction in water or an ether solution under reflux.
2. Chemical Reaction of Zinc Iodide
In an aqueous solution, zinc iodide forms various molecular species and acts as a Lewis acid in synthetic organic reactions. The Simmons-Smith reaction, utilizing zinc iodide, is notable for cyclopropanating alkenes.
3. Simmons-Smith Reaction
This reaction forms cyclopropane rings from alkenes using a zinc-copper couple and diiodomethane, producing the active species ICH2ZnI.
4. Toxicity of Zinc Iodide
With notable oral toxicity, zinc iodide requires careful handling under the guidelines of various safety laws, despite not being flammable.