Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Methyl iodide, also called iodomethane, and commonly abbreviated "MeI", is the chemical compound with the formula CH3I. This dense volatile liquid is related to methane by replacement of one hydrogen atom by an atom of iodine. Its dipole moment is 1.59 D, and its refractive index is 1.5304 (20 °C, D), 1.5293 (21 °C, D). Methyl iodide is miscible with common organic solvents. It is colourless, although upon exposure to light, samples develop a purplish tinge caused by the presence of I2. Storage over copper metal absorbs the iodine. Methyl iodide is widely used in organic synthesis to deliver a methyl group, via the transformation called methylation. It is naturally emitted by rice plantations in small amounts. It is also used as a pesticide.