polychlorides

Polychlorides are chemical species that contain more than one chlorine atom in their structure. The term is used across different areas of chemistry and can refer to both organic and inorganic compounds. In organic chemistry, polychlorides describe derivatives in which several hydrogen atoms of a hydrocarbon are replaced by chlorine. In inorganic and coordination chemistry, polychlorides often refer to metal chloride–rich species, including discrete chlorido complexes and chlorido-containing clusters.

In organic contexts, polychlorinated compounds are common products of chlorination reactions and have a wide range of applications and implications. Polychlorinated pesticides and solvents were historically important in industry but many polychlorinated organics are highly persistent in the environment and can be bioaccumulative. Well-known examples include polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). The properties of organic polychlorides—such as volatility, solubility, and persistence—depend on the number and pattern of chlorine substitutions.

In inorganic and coordination chemistry, polychlorides describe metal-containing species with several chloride ligands. These include various chlorido complexes and, in some cases, polynuclear chloride clusters. Such compounds are studied for their bonding, structural features, and reactivity, and they are often synthesized by salt-metathesis routes, ligand substitution, or controlled oxidation of chloride-rich precursors.

Environmental and regulatory considerations are prominent for many polychlorinated organics due to their persistence and potential health impacts. See also polychlorinated compounds and chlorination chemistry.