P 2337 (OTTO) Potassium iodide, GR 99%+ Cas 7681-11-0 - used in pharmaceutical formulations and in film photography as a source of iodine. P 2337 (OTTO) Potassium iodide, GR 99%+ Cas 7681-11-0 - used as a component in the electrolyte of dye sensitized solar cells. In the field of synthetic organic chemistry, it is used in the preparation of alkyl or aryl iodo compounds. It is employed as a nucleophilic catalyst in the alkylations with alkyl bromide, chloride, tosylate and mesylate. In the presence of acid it forms hydroiodic acid, which is a strong reducing agent.