Bischlorocarbonyl

Bischlorocarbonyl is a descriptive term used in organic chemistry to designate a molecule bearing two chlorocarbonyl groups (-COCl). It is not a single fixed compound, but a class descriptor applied to diacyl chlorides, often derived from dicarboxylic acids or related skeletons. In systematic terms, compounds of this type can be referred to as dichlorocarbonyl derivatives or as diacyl chlorides.

Well-known instances include oxalyl chloride (ethanedioyl dichloride), malonyl dichloride (propanedioyl dichloride), succinyl dichloride (butanedioyl dichloride), and sebacoyl dichloride (decanedioyl dichloride). These molecules all contain two -COCl groups, though the carbon skeleton between the two carbonyls differs. They are typically highly reactive, moisture sensitive, and lachrymatory due to the reactive acyl chloride functionality.

Preparation generally involves converting a corresponding dicarboxylic acid to its acid chloride using reagents such as thionyl chloride, oxalyl chloride, or phosphorus reagents. On exposure to water, they hydrolyze to the dicarboxylic acid and release hydrogen chloride. They are commonly liquids or low-melting solids at room temperature and are used as reactive intermediates in organic synthesis.

Applications of bischlorocarbonyl compounds include serving as bifunctional building blocks in polymer chemistry, where they react with diols or diamines to form polyesters or polyurethanes. The two acyl chloride groups enable chain extension or crosslinking, providing a route to durable, high-molecular-weight materials.

Note that “bischlorocarbonyl” is a descriptive label; most literature uses the specific diacyl chloride name (e.g., oxalyl chloride, sebacoyl dichloride) rather than a generic term.