Metüülhalogeenid

Metüülhalogeenid are a class of organic compounds with the general formula CH3X, where X represents a halogen atom. The halogens commonly encountered in this class are fluorine (F), chlorine (Cl), bromine (Br), and iodine (I). Thus, the specific compounds are methyl fluoride (CH3F), methyl chloride (CH3Cl), methyl bromide (CH3Br), and methyl iodide (CH3I). These compounds are the simplest alkyl halides, derived from methane by replacing one hydrogen atom with a halogen.

Methyl fluoride is a colorless gas with a faint ethereal odor. It finds limited use as a refrigerant and in organic synthesis. Methyl chloride is also a colorless gas, often used as a refrigerant and as an intermediate in the production of silicones and other chemicals. It was formerly used as a local anesthetic. Methyl bromide is a colorless gas that has been widely used as a fumigant for pest control, though its use is restricted due to its ozone-depleting properties. Methyl iodide is a volatile, colorless liquid that is a strong alkylating agent and is used in organic synthesis, particularly for introducing a methyl group into a molecule.

The physical properties of methylhalides vary with the halogen. For example, boiling points generally increase as the size and mass of the halogen atom increase, from methyl fluoride being a gas at room temperature to methyl iodide being a liquid. Their reactivity also differs, with methyl iodide being the most reactive in nucleophilic substitution reactions due to the weaker carbon-iodine bond compared to the carbon-fluorine bond in methyl fluoride.