Octachloronaphthalene

Synthesis

Polychlorinated naphthalene was prepared from naphthalene and phosphorus pentachloride as starting materials via a substitution reaction (Williamson reaction). All reagents used in the experiment were commercially available. The synthesis experiment using phosphorus pentachloride as the chlorinating agent was carried out in a pressure-resistant stainless steel reactor lined with polytetrafluoroethylene (PTFE).

Experimental procedure:

Naphthalene and phosphorus pentachloride were weighed and added to the PTFE-lined reactor, which was then sealed in a pressure-resistant stainless steel reactor and reacted at 260°C for 15 hours. After the reaction, the PTFE-lined reactor was removed and poured into ice water to remove unreacted PCI5. The insoluble solid was collected, washed with a small amount of water, dissolved in a small amount of toluene, dried with anhydrous MgSO4, filtered, and then an equal volume of anhydrous ethanol was added. The mixture was heated to reflux, filtered while hot, and then cooled to crystallize, yielding perchloronaphthalene. Mass spectrometry characterization was performed (spectrum shown below), with an average yield of 85%.

Chemical Properties

The chlorinated naphthalenes in which one or more hydrogen atoms have been replaced by chlorine to form wax-like substances, beginning with monochloronaphthalene and going on to the octachlor derivatives. Their physical states vary from mobile liquids to waxysolids depending on the degree of chlorination; freezing/ melting points of the pure compounds range from 17C for 1-chloronaphthalene to 198C for 1,2,3,4- tetrachloronaphthalene. 1-Chloro-isomer: Hazard identification (based on NFPA-704 M Rating System): Health 2, flammability 1, reactivity 0. 2-Chloro-isomer:

Uses

Chemical research; organic synthesis. According to HSDB (1005), U.S. has discontinued manufacturing of chlorinated naphthalenes since 1977. Chlorinated naphthalenes were formerly used as a wood preservative, additives in cutting oils, and as an additive in fireproofing and waterproofing cable insulation.

Uses

In electric cable insulation; additive to lubricants

Uses

Octachloronapthalene is a polychlorinated napththalene (PCN) produced via industrial thermal processes. It is a chemical pollutant present in the environment.

General Description

Pale yellow solid with an aromatic odor.

Air & Water Reactions

Insoluble in water.

Reactivity Profile

Contact with strong oxidizing agents may cause fire and explosion .

Health Hazard

The higher-chlorinated naphthalenes may cause severe injury to the liver.

Fire Hazard

Literature sources indicate that Octachloronaphthalene is nonflammable.

Safety Profile

Poison by inhalation, ingestion, and skin contact. When heated to decomposition it emits highly toxic fumes of Cl-. See also CHLORINATED HYDROCARBONS, AROMATIC.

Potential Exposure

Industrial exposure from individual chlorinated naphthalenes is rarely encountered; rather it usually occurs from mixtures of two or more Chlorinated naphthalenes. Due to their stability, thermoplasticity, and nonflammability, these compounds enjoy wide industrial application. These compounds are used in the production of electric condensers; in the insulation of electric cables and wires; as additives to extreme pressure lubricants; as supports for storage batteries; and as a coating in foundry use. octachloro-: Used as a fireproof and waterproof additive and lubricant additive. Pentachloro-: Used in electric wire insulation and in additives to special lubricants. tetrachloro-: Used in electrical insulating materials and as an additive in cutting oils. trichloro-: Used in lubricants and in the manufacture of insulation for electrical wire. Because of the possible potentiation of the toxicity of higher Chlorinated naphthalenes by ethanol and carbon tetrachloride, individuals who ingest enough alcohol to result in liver dysfunction would be a special group at risk. Individuals, e.g., analytical and synthetic chemists, mechanics and cleaners, who are routinely exposed to carbon tetrachloride or other hepatotoxic chemicals would also be at a greater risk than a population without such exposure. Individuals involved in the manufacture, utilization, or disposal of polychlorinated naphthalenes would be expected to have higher levels of exposure than the general population.

Source

Octachloronaphthalene was detected in various technical-grade PCB mixtures as impurities or by-products. Concentrations were 0.098 μg/g in PCB-1016, 0.433 μg/g in PCB- 1232, 0.378 μg/g in PCB-1248, 3.23 μg/g in PCB-1254, 55.5 μg/g in PCB-1260, and 50.5 μg/g in PCB-1262 (Yamashita et al., 2000).

Shipping

UN3082 Environmentally hazardous substances, liquid, n.o.s., Hazard class: 9; Labels: 9-Miscellaneous hazardous material, Technical Name Required.

Incompatibilities

All are incompatible with oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause fires or explosions. Keep away from alkaline materials, strong bases, strong acids, oxoacids, epoxides. Keep away from heat. Penta- is also incompatible with acids, alkalis.

Waste Disposal

High-temperature incineration with flue gas scrubbing. Incineration, preferably after mixing with another combustible fuel. Care must be exercised to assure complete combustion to prevent the formation of phosgene. An acid scrubber is necessary to remove the halo acids produced.