haloalkanoic

Haloalkanoic acids are carboxylic acids in which one or more hydrogen atoms on an alkyl chain are replaced by halogen atoms—fluorine, chlorine, bromine, or iodine. They form a broad class of compounds that includes monochloroacetic acid, fluoroacetic acid, dichloroacetic acid, and trichloroacetic acid. The halogen substituents are usually on the carbon framework attached to the carboxyl group, and can appear in varying numbers and positions, giving mono-, di-, and polyhaloalkanoic acids.

Nomenclature and examples: They are commonly named as haloalkan- carboxylic acids. well-known examples include monochloroacetic acid (MCAA, Cl–CH2–COOH), chloroacetic acids in general, monofluoroacetic acid (MFAA), dichloroacetic acid (DCAA), and trichloroacetic acid (TCAA). The position of the halogen atoms in the alkyl chain is also indicated in systematic names when needed.

Properties: The halogen atoms withdraw electron density through induction, stabilizing the conjugate base after deprotonation. As a result, haloalkanoic acids are typically stronger acids than the corresponding unsubstituted alkanoic acids, and acidity tends to increase with the number and electronegativity of halogen substituents. Physical properties vary with chain length and substitution, but many are highly soluble in water for smaller carbon backbones and range from liquids to solids. They are generally corrosive and can be hazardous.

Occurrence and uses: Haloalkanoic acids are versatile building blocks in organic synthesis and are used to prepare a wide range of intermediates, polymers, agrochemicals, and pharmaceuticals. A notable environmental aspect is the formation of haloacetic acids as disinfection byproducts in drinking water chlorination, which has prompted regulatory attention due to potential health effects.

Safety: These compounds are corrosive and can be toxic. Proper handling, storage, and disposal are required, with appropriate protective equipment and adherence to safety guidelines.