7572-29-4 Usage
Chemical Properties
DCA is a volatile, pyrophoric oil. It has an
unpleasant, sweetish odor. A gas above 32°C/90°F.
Uses
Different sources of media describe the Uses of 7572-29-4 differently. You can refer to the following data:
1. DCA is not commercially available in large quantities. It is
reportedly a by-product of the synthesis of vinylidene chloride
and is not known to be used commercially.
2. By-product in synthesis of
vinylidene chloride; decomposition product of
trichloroethylene under alkaline conditions
Production Methods
DCA is a highly toxic, spontaneously combustible, undesired,
and noncommercial product of the dehydrochlorination
of trichloroethylene. It has resulted from exposure of
trichloroethylene vapor to Hopcalite in a closed environmental
system (submarine) and soda lime in closed circuit
(rebreathing) anesthesia machines and from exposure of
trichloroethylene liquid to caustic in degreaser tanks. It
may also be an undesired by-product during chemical processes
such as production of vinylidene chloride.
When DCA was decomposed in the presence of oxygen,
seven substanceswere found: phosgene, hexachlorobutadiene,
chloroform, carbon tetrachloride, trichloroacetyl chloride,
tetrachloroethylene, and trichloroacryloyl chloride.
Synthesis Reference(s)
The Journal of Organic Chemistry, 52, p. 3461, 1987 DOI: 10.1021/jo00391a059
General Description
Volatile oil with a disagreeable, sweetish odor. Mp: -68 to -65°C; bp: 32-34°C. Density: 1.38 g cm-3. Is not produced commercially.
Air & Water Reactions
Ignites or explodes upon contact with air (MCA Case History 1989 (1974)).
Reactivity Profile
Dichloroethyne is a reducing agent. Incompatible with oxidizing agents. Can ignite or explode on contact with air or if heated. Can explode if shocked. Burns in the presence of chlorine to form phosgene (Ann. Chem. 640:5(1961)).
Health Hazard
Dichloroacetylene is a neurotoxin;
it is carcinogenic in experimental
animals.
Safety Profile
Confirmed carcinogen
with experimental carcinogenic data. Poison
by inhalation. Central nervous system
effects. Can be formed by thermal
decomposition (>70℃) from
trichloroethylene. Symptoms include a
disabling nausea and intense jaw pain.
Strong explosive when shocked or exposed
to heat or air. Can react vigorously with
oxidizing materials. When heated to
decomposition or on contact with acid or
acid fumes it emits highly toxic fumes of
Cl-. See also ACETYLENE
COMPOUNDS and CHLORINATED
HYDROCARBONS , ALIPHATIC.
Potential Exposure
DCA, dichloroacetylene, is not
produced commercially and is a possible decomposition
product of trichloroethylene or trichloroethane. Reported to
be a by-product of vinylidene chloride (see V:0220). Also,
a closed circuit anesthesia with trichloroethylene, heat and
moisture produced by soda-lime absorption of CO2 may
produce dichloroacetylene (DCA) along with phosgene and
carbon monoxide (CO).
Carcinogenicity
The IARC concluded that there
is limited evidence for the carcinogenicity of DCA to experimental
animals based on treatment-related increases in the
incidence of adenocarcinomas of the kidney in male mice,
benign tumors of the liver and kidney, and an increased
incidence of lymphomas in rats.
Metabolic pathway
By the incubation of dichloroacetylene with rat liver
and kidney subcellular fractions, the formation of S-
(1,2-dichlorovinyl)glutathione (DCVG) is observed, and
N-acetyl-S-(1,2-dichlorovinyl)-L-cysteine is identified as
a urinary metabolite in rats.
Shipping
Explosive! Dichloroacetylene is cited by DOT
as “FORBIDDEN.”
Incompatibilities
An unstable explosive; heat or
shock may cause explosion. Incompatible with oxidizers
(chlorates, nitrates, peroxides, permanganates, perchlorates,
chlorine, bromine, fluorine, etc.); contact may cause fires
or explosions. Keep away from alkaline materials, strong
acids (forms poisonous gases of phosgene and hydrogen
chloride), strong bases.
Check Digit Verification of cas no
The CAS Registry Mumber 7572-29-4 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 7,5,7 and 2 respectively; the second part has 2 digits, 2 and 9 respectively.
Calculate Digit Verification of CAS Registry Number 7572-29:
(6*7)+(5*5)+(4*7)+(3*2)+(2*2)+(1*9)=114
114 % 10 = 4
So 7572-29-4 is a valid CAS Registry Number.
InChI:InChI=1/C2Cl2/c3-1-2-4
7572-29-4Relevant articles and documents
The C-Cl bond fissions from the photolysis of CHClCCl2 at 193 nm
Lee, Yu-Jinn,Lee, Ya-Rong,Chou, Chih-Chiang,Lin, Shen-Maw
, p. 346 - 347 (2007/10/03)
The photolysis of CHClCCl2 at 193 nm was investigated by translational spectroscopy. Two distinct product translational distributions were derived for the C-Cl bond fissions. The internally excited C2HCl2 fragment from the main dissociation channel is shown to decompose totally to produce the Cl+C2HCl products.
IR Laser-induced Chemistry of some Perhaloethene-Silane Mixtures at Different Single Irradiating Wavelengths
Pola, Josel,Simeonov, Sawa
, p. 101 - 108 (2007/10/02)
TEA CO2 laser-induced reactions in chlorotrifluoroethene-silane, 1,2-dichlorodifluoroethene-silane, 1,1-dichlorodifluoroethene-silane, and 1,2-dichlorodifluoroethene-trimethylsilane mixtures at medium (4-19 Torr) and in chlorotrifluoroethene-silane and 1,2-dichlorodifluoroethene-silane mixtures at low (1 Torr) pressures can be initiated by irradiation tuned to either perhaloethene or silane.The reaction progress at medium pressure and reaction products at low pressure depend on the particular wavelength employed.The former reactions are assumed to occur through reactive collision of both energized components in the mixture and have been shown to yield mostly tetrafluorosilane, trifluorosilane, hydrogen chloride, and other hydrocarbons.The latter are explained by multiphoton dissociation of the alkene into carbenes, subsequent reactions of these carbenes, and by 1,2-rearrangement of halogen in the transient CFCl=CF* radical produced upon C-Cl bond cleavage of the parent CFCl=CFCl compound.This reaction mechanism is in line with IR multiphoton decomposition of 1,2-dichlorodifluoroethene both in the absence and presence of chlorine and carbon monoxide.
Infrared Spectra of Hydrogen-Bonded ? Complexes between Hydrogen Halides and Acetylene
McDonald, Stephen A.,Johnson, Gary L.,Keelan, Brian W.,Andrews, Lester
, p. 2892 - 2896 (2007/10/02)
Hydrogen-bonded ? complexes C2H2--H-X have been formed by codeposition of C2H2 and HX in excess argon at 15 K and by vacuum-UV photolysis of vinyl halides.The strength of the hydrogen bond, as measured by the displacement of the H-X vibrational fundamental below the isolated HX value, decreases in the series HF, HCl, and HBr as expected.Similar complexes made from di- and thichloroethylenes give slightly higher H-Cl vibrations which show minimal interaction between the halide and the acetylene substituent.The H-F fundamentals for C2H4 and C2H2 complexes at 3732 and 3747 cm-1, respectively, show that the ? electrons in double and triple bonds are comparable hydrogen-bond acceptors.
