Pentachlorobenzene

Structural formula
General
Surname	Pentachlorobenzene
other names	Pentachlorobenzene Quintochlorobenzene QCB PeCB
Molecular formula	C 6 HCl 5
Brief description	colorless, highly flammable solid
External identifiers / databases
CAS number 608-93-5 EC number 210-172-0 ECHA InfoCard 100.009.248 PubChem 11855 ChemSpider 21106570 Wikidata Q425468
properties
Molar mass	250.34 g mol −1
Physical state	firmly
density	1.609 g cm −3 (25 ° C)
Melting point	84-87 ° C
boiling point	275-277 ° C
Vapor pressure	133 Pa (98.6 ° C)
solubility	practically insoluble in water (0.83 mg l −1 at 25 ° C)
safety instructions
GHS hazard labeling from  Regulation (EC) No. 1272/2008 (CLP) , expanded if necessary danger H and P phrases H: 228-302-410 P: 210-273-501
Toxicological data	1080 mg kg −1 ( LD 50 ,  rat ,  oral )
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Pentachlorobenzene is a chemical compound from the group of aromatic chlorinated hydrocarbons . In 2009 it was included in Appendices A and C of the Stockholm Convention .

Extraction and presentation

Pentachlorobenzene is obtained as a by-product in the production of tetrachlorobenzenes and can be extracted by subsequent distillation and crystallization. The direct production of pure pentachlorobenzene is practically impossible due to the parallel formation of compounds with different levels of chlorination. Since it is generally produced in small quantities during the chlorination of benzene , it is also contained in other chlorobenzenes (tetrachlorobenzenes, hexachlorobenzene , ...).

use

Pentachlorobenzene was used as an intermediate product in the manufacture of the pesticide and disinfectant pentachloronitrobenzene ( quintozene ). Since this compound has been banned in Germany since 1992 (since 2002 in the EU), the production of pentachlorobenzene was also discontinued. Nevertheless, pentachlorobenzene was detected in low concentrations in German waters (for example the Rhine) in 2006.

safety instructions

Pentachlorobenzene is one of the long-lived organic pollutants (only anaerobic degradation), which enables it to accumulate in the food chain (see also the Stockholm Convention ). It is very toxic to aquatic organisms, highly flammable and decomposes when heated or when burned, producing toxic, corrosive vapors ( hydrogen chloride , phosgene ). During thermal decomposition, polychlorodibenzo- p- dioxins and polychlorodibenzofurans can be formed in the presence of oxygen .

proof

Pentachlorobenzene can be detected by solid phase extraction and subsequent GC / ECD analysis up to a limit of 0.025 µg / l for aqueous samples.

Web links

• German Pollutant Release and Transfer Register: Pentachlorobenzene
• Environmental Health Criteria (EHC) for Chlorobenzenes other than Hexachlorobenzene

See also

• Pentachlorobenzenethiol (C ₆ Cl ₅ SH)
• Pentachlorophenol (C ₆ Cl ₅ OH)
• Pentachloroaniline (C ₆ Cl ₅ NH ₂ )
• Pentachloroanisole (C ₆ Cl ₅ OCH ₃ )
• Pentabromobenzene (C ₆ HBr ₅ )
• Pentafluorobenzene (C ₆ HF ₅ )
• Pentaiodbenzene (C ₆ HI ₅ )

Individual evidence

1. ↑ ^{a b c d e f} Entry on pentachlorobenzene in the GESTIS substance database of the IFA , accessed on February 14, 2017(JavaScript required) .
2. ↑ ^{a b} Environmental Health Criteria (EHC) for Chlorobenzenes other than Hexachlorobenzene , accessed March 6, 2017.
3. ↑ Entry on Pentachlorobenzene in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
4. ↑ Pentachlorobenzene data sheet from Sigma-Aldrich , accessed on April 18, 2011 ( PDF ).
5. ↑ Press Release - COP4 - Geneva, 8 May 2009: Governments unite to step-up reduction on global DDT reliance and add nine new chemicals under international treaty , 2009.
6. ↑ ^{a b c} Emission reduction for priority and priority hazardous substances of the Water Framework Directive - material data sheets - data sheet pentachlorobenzene , texts 29/07, environmental research plan of the Federal Minister for the Environment, Nature Conservation and Nuclear Safety, p. 373ff.