1,2-Dichloroethylene

1,2-Dichloroethylene
Skeletal formula of cis-1,2-dichloroethene
Skeletal formula of cis-1,2-dichloroethene
Skeletal formula of trans-1,2-dichloroethene
Skeletal formula of trans-1,2-dichloroethene
Ball-and-stick model of cis-1,2-dichloroethene
Ball-and-stick model of cis-1,2-dichloroethene
cis-1,2-Dichloroethene (Z)
Ball-and-stick model of trans-1,2-dichloroethene
Ball-and-stick model of trans-1,2-dichloroethene
trans-1,2-Dichloroethene (E)
Names
Preferred IUPAC name
1,2-Dichloroethene
Other names
1,2-Dichloroethene
1,2-DCE
Acetylene dichloride
sym-Dichloroethylene
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.007.956 Edit this at Wikidata
EC Number
  • 208-750-2
KEGG
UNII
  • InChI=1S/C2H2Cl2/c3-1-2-4/h1-2H checkY
    Key: KFUSEUYYWQURPO-UHFFFAOYSA-N checkY
  • InChI=1/C2H2Cl2/c3-1-2-4/h1-2H/b2-1-
    Key: KFUSEUYYWQURPO-UPHRSURJBI
  • InChI=1/C2H2Cl2/c3-1-2-4/h1-2H
    Key: KFUSEUYYWQURPO-UHFFFAOYAW
  • Cl[C@H]=CCl
  • ClC=CCl
Properties
C2H2Cl2
Molar mass 96.95 g/mol
Appearance colorless liquid
Odor sweet[1]
Density Z: 1.28 g/cm3
E: 1.26 g/cm3
Melting point Z: −81.47 °C
E: −49.44 °C
Boiling point Z: 60.2 °C
E: 48.5 °C
  • −51.0·10−6 cm3/mol (cis)
  • −48.9·10−6 cm3/mol (trans)
Z: 1.9 D
E: 0 D
Hazards
Flash point 2–4 °C; 36–39 °F; 275–277 K
Explosive limits 5.6–12.8%[2]
Lethal dose or concentration (LD, LC):
770 mg/kg (oral, rat)
1275 mg/kg (oral, rat, trans-isomer)[3]
21,273 ppm (mouse, 6 hr, trans-isomer)[3]
16,000 ppm (rat, 6 hr, cis-isomer)[3]
NIOSH (US health exposure limits):
PEL (Permissible)
 TWA 200 ppm (790 mg/m3)[2]
REL (Recommended)
 TWA 200 ppm (790 mg/m3)[2]
IDLH (Immediate danger)
 1000 ppm[2]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

1,2-Dichloroethylene or 1,2-DCE is the name for a pair of organochlorine compounds with the molecular formula C2H2Cl2. The two compounds are isomers, each being colorless liquids with a sweet odor. It can exist as either of two geometric isomers, cis-1,2-dichloroethene or trans-1,2-dichloroethene, but is often used as a mixture of the two. They have modest solubility in water. These compounds have some applications as a degreasing solvent.[1] In contrast to most cis-trans compounds, the Z isomer (cis) is more stable than the E isomer (trans) by 0.4 kcal/mol.[4]

Production, uses and reactions

cis-DCE, the Z isomer, is obtainable by the controlled chlorination of acetylene:

C2H2 + Cl2 → C2H2Cl2

Industrially both isomers arise as byproducts of the production of vinyl chloride, which is produced on a vast scale. Unlike 1,1-dichloroethylene, the 1,2-dichloroethylene isomers do not polymerize.[1]

trans-1,2-DCE has applications including electronics cleaning, precision cleaning, and certain metal cleaning applications.[5]

Both isomers participate in Kumada coupling reactions. trans-1,2-Dichloroethylene participates in cycloaddition reactions.[6]

Safety and environmental concerns

These compounds have "moderate oral toxicity to rats".[1]

The dichloroethylene isomers occur in some polluted waters and soils, as the decomposition products of trichloroethylene. Significant attention has been paid to their further degradation, e.g. by iron particles.[7][8]

See also

References

  1. ^ a b c d E.-L. Dreher; T. R. Torkelson; K. K. Beutel (2011). "Chlorethanes and Chloroethylenes". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.o06_o01. ISBN 978-3527306732.
  2. ^ a b c d e NIOSH Pocket Guide to Chemical Hazards. "#0195". National Institute for Occupational Safety and Health (NIOSH).
  3. ^ a b c "1,2-Dichloroethylene". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
  4. ^ Pitzer, Kenneth S.; Hollenberg, J. L. (1954). "cis- and trans-Dichloroethylenes. The Infrared Spectra from 130–400 Cm.–1 and the Thermodynamic Properties". J. Am. Chem. Soc. 76 (6): 1493–1496. doi:10.1021/ja01635a010.
  5. ^ "Chlorinated Solvents and Feed Stock - Axiall". Archived from the original on 2016-04-08. Retrieved 2016-03-23.
  6. ^ Wang, Xiao Min; Hou, Xuelong; Zhou, Zhongyuan; Mak, Thomas C. W.; Wong, Henry N. C. (1993). "Arene synthesis by extrusion reaction. 16. Coplanar and stable derivatives of 13,14-didehydro-tribenzo[a,c,e]cyclooctene: Synthesis of 5,6-didehydro-1,1,14,14-tetramethyl-10,11-methano-1H-benzo[5,6]cycloocta[1,2,3,4-def]fluorene and 5,6-didehydro-10,11-methano-1H-benzo[5,6]cycloocta[1,2,3,4-def]fluorene-1,14-dione and x-ray crystal structures of 1,1,14,14-tetramethyl-10,11-methano-1H-benzo[5,6-cycloocta[1,2,3,4-def]fluorene and 1,12-dihydro-1,1,12,12-tetramethyldicyclopenta[def,JKL]tetraphenylene". The Journal of Organic Chemistry. 58 (26): 7498–7506. doi:10.1021/jo00078a031.
  7. ^ Mattes, Timothy E.; Alexander, Anne K.; Coleman, Nicholas V. (2010). "Aerobic biodegradation of the chloroethenes: Pathways, enzymes, ecology, and evolution". FEMS Microbiology Reviews. 34 (4): 445–475. doi:10.1111/j.1574-6976.2010.00210.x. PMID 20146755.
  8. ^ Schrick, Bettina; Blough, Jennifer L.; Jones, A. Daniel; Mallouk, Thomas E. (2002). "Hydrodechlorination of Trichloroethylene to Hydrocarbons Using Bimetallic Nickel−Iron Nanoparticles". Chemistry of Materials. 14 (12): 5140–5147. doi:10.1021/cm020737i.