Organomercury chemistry refers to the study of organometallic compounds that contain mercury. Typically the Hg–C bond is stable toward air and moisture but sensitive to light. Important organomercury compounds are the methylmercury(II) cation, CH3Hg+; ethylmercury(II) cation, C2H5Hg+; dimethylmercury, (CH3)2Hg, diethylmercury and merbromin ("Mercurochrome"). Thiomersal is used as a preservative for vaccines and intravenous drugs.
The toxicity of organomercury compounds[1][2] presents both dangers and benefits. Dimethylmercury in particular is notoriously toxic, but found use as an antifungal agent and insecticide. Merbromin and phenylmercuric borate are used as topical antiseptics, while thimerosal is safely used as a preservative for vaccines and antitoxins.[3]