118-74-1 Usage
Uses
Used in Agricultural Industry:
Hexachlorobenzene is used as a fungicide for seed treatment, particularly for onions, sorghum, wheat, and other grains. It helps protect seeds from fungal infections, ensuring healthy plant growth.
Used in Chemical Synthesis:
Hexachlorobenzene serves as an intermediate in organic synthesis, aiding in the production of various organic chemicals and contributing to the development of new compounds.
Used in Manufacturing Industry:
In the past, hexachlorobenzene was used as a chemical intermediate in dye manufacturing, the synthesis of other organic chemicals, and the production of pyrotechnic compositions for military applications. It was also utilized as a raw material for synthetic rubber, a plasticizer for polyvinyl chloride, a porosity controller in the manufacture of electrodes, and a wood preservative.
Synthesis Reference(s)
Journal of the American Chemical Society, 69, p. 3146, 1947 DOI: 10.1021/ja01204a507
Air & Water Reactions
HEXACHLOROBENZENE is sensitive to moisture. Insoluble in water.
Reactivity Profile
HEXACHLOROBENZENE reacts violently with dimethylformamide. .
Hazard
Possible carcinogen. Toxic by ingestion.
Combustible.
Health Hazard
Harmful by dust inhalation or if swallowed. Irritating to eyes, skin and mucous membranes. Prolonged periods of ingestion may cause cutaneous porphyria.
Health Hazard
The acute oral and inhalation toxicity ofhexachlorobenzene is low in test animals.Repeated ingestion of this compound mayproduce porphyria hepatica (increased for mation and excretion of porphyrin) causedby disturbances in liver metabolism. The oralLD50 value in rabbits is 2600 mg/kg; theinhalation LC50 value from a single exposureis 1800 mg/m3 (NIOSH 1986). The occupa tional health hazard from inhalation shouldbe very low because of its very low vaporpressure (0.00001 torr).Hexachlorobenzene causes cancer in ani mals. Oral administration of this compoundfor 18 weeks to 2 years caused tumors inthe liver, kidney, thyroid, and blood in rats,mice, and hamsters. It is a suspected humancarcinogen, evidence of which occurs to alimited extent.
Fire Hazard
Noncombustible solid; very low reactiv ity. Reaction with dimethyl formamide is
reported to be violent at temperatures above
65°C (149°F) (NFPA 1997).
Potential Exposure
Hexachlorobenzene was used as a fun gicide; an additive for pyrotechnic compositions; and as
wood preservative. It was used widely as a pesticide to pro tect seeds of onions and sorghum, wheat, and other grains
against fungus until 1965. This material was used to make
fireworks; ammunition for military uses; synthetic rubber;
as a porosity controller in the manufacture of electrodes; as
an intermediate in dye manufacture; in organic synthesis. It
is formed as a by-product of making other chemicals; in
the waste streams of chloralkali and wood-preserving
plants; and when burning municipal waste. Currently, there
are no commercial uses of hexachlorobenzene in the United
States.
Carcinogenicity
Hexachlorobenzene is reasonably anticipated to be a human carcinogen based on sufficient evidence of carcinogenicity from studies in experimental animals.
Source
Hexachlorobenzene may enter the environment from incomplete combustion of
chlorinated compounds including mirex, kepone, chlorobenzenes, pentachlorophenol, PVC,
polychlorinated biphenyls, and chlorinated solvents (Ahling et al., 1978; Dellinger et al., 1991). In
addition, hexachlorobenzene may enter the environment as a reaction by-product in the production
of carbon tetrachloride, dichloroethylene, hexachlorobutadiene, trichloroethylene, tetrachloroethylene,
pentachloronitrobenzene, and vinyl chloride monomer (quoted, Verschueren, 1983).
Environmental Fate
Biological. Reductive monodechlorination occurred in an anaerobic sewage sludge yielding principally 1,3,5-trichlorobenzene. Other compounds identified included pentachlorobenzene, 1,2,3,5-tetrachlorobenzene and dichlorobenzenes (Fathepure et al., 1988). In activated sludge, only 1.5% of the applied hexachlorobenzene mineralized to carbon dioxide after 5 days (Freitag et al., 1985). In a 5-day experiment, 14C-labeled hexachlorobenzene applied to soil-water suspensions under aerobic and anaerobic conditions gave 14CO2 yields of 0.4 and 0.2%, respectively (Scheunert et al., 1987).When hexachlorobenzene was statically incubated in the dark at 25°C with yeast extract and settled domestic wastewater inoculum, no signi?cant biodegradation was observed. At a concentration of 5 mg/L, percent losses after 7, 14, 21 and 28-day incubationGroundwater. According to the U.S. EPA (1986) hexachlorobenzene has a high potential to leach to groundwater.Photolytic. Solid hexachlorobenzene exposed to arti?cial sunlight for 5 months photolyzed at a very slow rate with no decomposition products identified (Plimmer and Klingebiel, 1976). The sunlight irradiation of hexachlorobenzene (20 g) in a 100 mL borosilicate glass-stoppered Erlenmeyer ?ask for 56 days yielded 64 ppm pentachlorobiphenyl (Uyeta et al., 1976). A carbon dioxide yield <0.1% was observed when hexachlorobenzene adsorbed on silica gel was irradiated with light (λ >290 nm) for 17 hours (Freitag et al., 1985).Irradiation (λ ≥285 nm) of hexachlorobenzene (1.1–1.2 mM/L) in an acetonitrile-water mixture containing acetone (concentration = 0.553 mM/L) as a sensitizer gave the following products (% yield): pentachlorobenzene (71.0), 1,2,3,4-tetrachlorobenzene (0.6)
Metabolic pathway
With the incubation of rat liver microsomes,
hexachlorobenzene is metabolized to give
pentachlorophenol and tetrachlorohydroquinone, and,
in addition, a considerable amount of covalent binding
to protein is detected (250 pM pentachlorophenol,
17 pM tetrachlorohydroquinone, and 11 pM
tetrachlorobenzoquinone covalent binding in an
incubation containing 50 μM hexachlorobenzene).
Metabolism
Sensitized photolysis of HCB at wavelengths greater
than 285 nm in acetonitrile/water containing acetone gave
dechlorinated products: pentachlorobenzene (78) (71%),
1,2,3,4-tetrachlorobenzene (79) (0.6%), 1,2,3,5-tetrachlorobenzene
(80) (2.2%), and 1,2,4,5- tetrachlorobenzene
(81) (3.7%). Without acetone, products included
pentachlorobenzene (78) (76.8%), 1,2,3,5-tetrachlorobenzene
(80) (1.2%), 1,2,4,5- tetrachlorobenzene (81) (1.7%),
and 1,2,4-trichlorobenzene (82) (0.2%) (105).
Irradiation of hexachlorobenzene in methanol solution
at wavelengths greater than 260 nm gave a
mixture of reductively dechlorinated products (pentachlorobenzene
and a tetrachlorobenzene, probably 80)
and pentachlorobenzyl alcohol 83, and also a tetrachlorodi(
hydroxymethyl)benzene (106). A similar product
mixture was obtained by exposing a methanolic solution of
hexachlorobenzene inmethanol to sunlight outdoors. After
15 days, only 30% of hexachlorobenzene was recovered.
Photolysis rates were enhanced by the addition of sensitizers
(diphenylamine, tryptophane, and naturally occurring
organic substances), but no products were identified.
In an anaerobic sewage sludge, hexachlorobenzene was
reductively dechlorinated and the principal product was
1,3,5-trichlorobenzene (84). Pentachlorobenzene, 1,2,3,5-
tetrachlorobenzene, and dichlorobenzenes were also identified
(107). In activated sludge, 1.5% of hexachlorobenzene
was mineralized as carbon dioxide after 5 days.
Solubility in organics
In millimole fraction at 25 °C: 2.62 in n-hexane, 3.14 in n-heptane, 3.71 in n-octane, 4.10 in nnonane,
4.60 in n-decane, 6.81 in n-hexadecane, 2.95 in cyclohexane, 3.87 in methylcyclohexane,
2.52 in 2,2,4-trimethylpentane, 4.71 in tert-butylcyclohexane, 4.40 in dibutyl ether, 3.20
in methyl tert-butyl ether, 5.92 in tetrahydrofuran, 3.97 in 1,4-dioxane, 0.0902 in methanol,
0.236 in ethanol, 0.398 in 1-propanol, 0.298 in 2-propanol, 0.667 in 1-butanol, 0.521 in 2-
butanol, 0.533 in 2-methyl-1-propanol, 0.517 in 2-methyl-2-propanol, 1.03 in 1-pentanol, 0.860
in 2-propanol, 0.770 in 3-methyl-1-butanol, 1.20 on 2-methyl-2-butanol, 1.44 in 1-hexanol, 1.40
in 2-methyl-1-pentanol, 1.43 in 4-methyl-2-pentanol, 1.90 in 1-heptanol, 2.38 in 1-octanol, 1.74
in 2-ethyl-1-hexanol, 3.80 in 1-decanol, 0.920 in cyclopentanol, 3.65 in butyl acetate, 2.11 in
ethyl acetate, 1.48 in methyl acetate, 2.86 in 1,2-dichloroethane, 3.83 in 1-chlorobutane, 5.08 in
1-chlorohexane, 6.06 in 1-chlorooctane, 6.10 in chlorocyclohexane (De Fina et al., 2000)
Solubility in water
In millimole fraction at 25 °C: 2.62 in n-hexane, 3.14 in n-heptane, 3.71 in n-octane, 4.10 in nnonane,
4.60 in n-decane, 6.81 in n-hexadecane, 2.95 in cyclohexane, 3.87 in methylcyclohexane,
2.52 in 2,2,4-trimethylpentane, 4.71 in tert-butylcyclohexane, 4.40 in dibutyl ether, 3.20
in methyl tert-butyl ether, 5.92 in tetrahydrofuran, 3.97 in 1,4-dioxane, 0.0902 in methanol,
0.236 in ethanol, 0.398 in 1-propanol, 0.298 in 2-propanol, 0.667 in 1-butanol, 0.521 in 2-
butanol, 0.533 in 2-methyl-1-propanol, 0.517 in 2-methyl-2-propanol, 1.03 in 1-pentanol, 0.860
in 2-propanol, 0.770 in 3-methyl-1-butanol, 1.20 on 2-methyl-2-butanol, 1.44 in 1-hexanol, 1.40
in 2-methyl-1-pentanol, 1.43 in 4-methyl-2-pentanol, 1.90 in 1-heptanol, 2.38 in 1-octanol, 1.74
in 2-ethyl-1-hexanol, 3.80 in 1-decanol, 0.920 in cyclopentanol, 3.65 in butyl acetate, 2.11 in
ethyl acetate, 1.48 in methyl acetate, 2.86 in 1,2-dichloroethane, 3.83 in 1-chlorobutane, 5.08 in
1-chlorohexane, 6.06 in 1-chlorooctane, 6.10 in chlorocyclohexane (De Fina et al., 2000)
Shipping
UN2729 Hexachlorobenzene, Hazard Class: 6.1;
Labels: 6.1-Poisonous materials.
Purification Methods
Crystallise hexachlorobenzene repeatedly from *benzene. Dry it under vacuum over P2O5. [Beilstein 5 H 205, 5 IV 670.]
Degradation
Hexachlorobenzene is very stable and is unreactive toward acids and
bases.
Photolysis is very slow and in artificial sunlight, solid HCB photodecomposed
after 5 months. In sunlight, 20 g of HCB contained in a borosilicate flask gave a concentration of 64 mg kg-1 of pentachlorobiphenyl
after 56 days (Uyeta et al., 1976).
Sensitised photolysis of HCB in an acetonitrile/water mixture containing
acetone at wavelengths greater than 285 nm gave the following products:
pentachlorobenzene (2) (71%), 1,2,3,4-tetrachlorobenzene (3)
(0.6%), 1,2,3,5-tetrachlorobenzene (4) (2.2%) and 1,2,4,5-tetrachlorobenzene
(5) (3.7%). In the absence of acetone, products identified included
2 (76.8%), 4 (1.2%), 5 (1.7%) and 1,2,4-trichlorobenzene (6) (0.2%)
(Choudhry and Hutzinger, 1984) (see Scheme 1).
Toxicity evaluation
There are no reports of avian casualties, although raptors
found dead in The Netherlands had substantial levels
of HCB in their livers along with cyclodiene and DDE
residues (33). The same authors reported porphyria in
quail following a 3-month dosing period with 20-ppm
HCB. Product registrations in Canada at the time allowed
up to 1000 ppm on various cereal seeds. In the early
1970s, levels in the range of 3–4 ppm (fresh weight
basis) were seen in eggs of fish-eating birds of the
Great Lakes and likely contributed to the high levels
of embryonic mortality seen (34). However, because HCB
is also an intermediate in the manufacture of several
chemicals, industrial pollution rather than use of the
chemical on farm fields could have been the source of
the contamination.
Incompatibilities
Reacts violently with oxidizers; dimethyl
formamide above 65 ℃.
Waste Disposal
Incineration is most effective
@ 1300 ℃ and 0.25 seconds. Consult with environmental
regulatory agencies for guidance on acceptable disposal
practices. Generators of waste containing this contaminant
(≥100 kg/mo) must conform to EPA regulations governing
storage, transportation, treatment, and waste disposal.
Check Digit Verification of cas no
The CAS Registry Mumber 118-74-1 includes 6 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 3 digits, 1,1 and 8 respectively; the second part has 2 digits, 7 and 4 respectively.
Calculate Digit Verification of CAS Registry Number 118-74:
(5*1)+(4*1)+(3*8)+(2*7)+(1*4)=51
51 % 10 = 1
So 118-74-1 is a valid CAS Registry Number.
InChI:InChI=1/C6Cl6/c7-1-2(8)4(10)6(12)5(11)3(1)9
118-74-1Relevant articles and documents
Influence of variation in combustion conditions on the primary formation of chlorinated organic micropollutants during municipal solid waste combustion
Wikstroem,Tysklind,Marklund
, p. 4263 - 4269 (1999)
The aim of this study was to investigate the influence of variation in combustion conditions on the primary formation of organic micropollutants (OMPs). The flue gas samples were taken at a relatively high flue gas temperature (650°C), to enable mechanistic studies on the high temperature formation (primary formation). Eleven experiments were performed in a laboratory scale fluidized bed reactor fed with an artificial municipal solid waste (MSW). The samples were analyzed for mono- to octachlorinated dibenzo- p-dioxins and dibenzofurans (CDDs/Fs), tri- to decachlorinated biphenyls (CBs), di- to hexachlorinated benzenes (CBzs), and di- to pentachlorinated phenols (CPhs). In addition to chlorinated OMPs, nonchlorinated dibenzo-p- dioxin (DD), dibenzofuran (DF), and biphenyl (BP) were analyzed. The experiments show that variations in the CE influence the degree of chlorination of the organic micropollutants. A correlation between low CE and formation of non- and low-chlorinated DMPs was seen and a distinct relationship of higher chlorinated homologues and efficient combustion condition. Thus, the DiCDFs and DiCBzs are formed during low combustion efficiency (CE), while the PeCDF and PeCBzs formation take place at higher CE. The distribution between primary and secondary air is important for the formation of higher CDD/Fs and CBzs. The primary formation of CDDs and CDFs is through different mechanisms. The CDDs are mainly formed by condensation of CPhs, while the CDFs are formed through a non- or a low-chlorinated precursor followed by further chlorination reactions.
Formation of PCDDs and PCDFs during the combustion of polyvinylidene chloride and other polymers in the presence of HCl
Ohta, Minoru,Oshima, Shozo,Osawa, Naoki,Iwasa, Toshio,Nakamura, Tadashi
, p. 1521 - 1531 (2004)
PVDC and three non-chlorinated polymers (PP, PET, and PA) were incinerated at 700-850°C in a laboratory-scale quartz tubular furnace in the presence of HCl (ca. 500 ppm?0.8 mg/l), and the gas-phase formation of PCDD/Fs, their putative precursors and their homologue profiles were investigated. The addition of HCl had little or no apparent effect on the level of PCDD/Fs formation during PVDC combustion, and their homologue profiles were quite different from those of the three non-chlorinated polymers. With PVDC, O 8CDD and particularly O8CDF were by far most prevalent, apparently as a result of the selective formation of the precursors. With each of the three non-chlorinated polymers, combustion at 800°C or higher in the presence of HCl resulted in PCDD/Fs formation at levels equaling or exceeding those observed with PVDC. In trials made with one of them (PP) under the same conditions but using a large polymer sample (100 mg vs 20 mg in all other trials), the level of PCDD/Fs formation was far higher than with the smaller polymer samples, and thus demonstrated the importance of appropriate combustion conditions for polymer incineration.
Copper-catalyzed chlorination and condensation of acetylene and dichloroacetylene
Taylor, Philip H.,Wehrmeier, Andreas,Sidhu, Sukh S.,Lenoir, Dieter,Schramm,Kettrup
, p. 1297 - 1303 (2000)
The chlorination and condensation of acetylene at low temperatures is demonstrated using copper chlorides as chlorinated agents coated to model borosilicate surfaces. Experiments with and without both a chlorine source and borosilicate surfaces indicate the absence of gas-phase and gas-surface reactions. Chlorination and condensation occur only in the presence of the copper catalyst. C2 through C8 organic products were observed in the effluent; PCDD/F were only observed from extraction of the borosilicate surfaces. A global reaction model is proposed that is consistent with the observed product distributions. Similar experiments with dichloroacetylene indicate greater reactivity in the absence of the copper catalyst. Reaction is observed in the gas-phase and in the presence of borosilicate surfaces at low temperatures. The formation of hexachlorobenzene is only observed in the presence of a copper catalyst. PCDD/F were only observed from extraction of the borosilicate surfaces. A global reaction model is proposed for the formation of hexachlorobenzene from dichloroacetylene. (C) 2000 Elsevier Science Ltd.
Reactions of selected molecular anions with oxygen
Knighton,Bognar,Grimsrud
, p. 557 - 562 (1995)
An investigation of the gas-phase reactions of molecular oxygen with the molecular anions of 17 compounds formed by resonance electron capture was undertaken using a pulsed e-beam high-pressure mass spectrometer. The molecular anions of sulphur hexafluoride, perfluromethylcyclohexane, cis- and trans-perfluorodecalin, m-chloronitrobenzene, o, m-and p-fluoronitrobenzene and o-, m- and p-dinitrobenzene were found to be unreactive towards oxygen. Those of o- and p-chloronitrobenzene, penta- and perchlorobenzene, perfluorobenzene, and perfluoratoluene were found to react readily with oxygen The second-order rate constants for these reactions are shown to bear so inverse dependence on temperature. The reactions involving o- and p-chloronitrabenezene and penta-and perchlorobenzene proceed via a branched mechanism by which an ion of the type [M + O - Cl]- and Cl- ion are simultaneously produced. A greater variety of negative ions are formed in the reactions of the molecular anions of perfluorobenzene and perfluorotoluene with oxygen The electron affinities of pentachlorobenzene (0.7 eV) and perchlorobenzene (1.0 eV) are also reported for the first time.
Removal of dioxins and related aromatic hydrocarbons from flue gas streams by adsorption and catalytic destruction
Liljelind, Per,Unsworth, John,Maaskant, Onno,Marklund, Stellan
, p. 615 - 623 (2001)
The dioxin removing capacity of the shell dedioxin system (SDDS a - Ti/V oxidative type catalyst) has been tested using the Umefa lab-scale incinerator over the temperature range 100 -230°C and at space velocities of 8000 and 40,000 h-1. Other analogous organic compounds, such as PCBs, PAHs, chlorobenzenes and chlorophenols have also been investigated. Results show a high degree of dioxin removal already at 100°C (82%), which occurs mainly by adsorption. When the temperature is raised a transition towards destruction is seen and at 150°C, gas hour space velocity (GHSV) 8000 and at 230°C, GHSV 40,000 virtually all removal is by destruction. High PCDD/F destruction efficiencies are reported (> 99.9%, based on I-TEQ); the other dioxin-related species and PAHs are also removed and destroyed to a significant extent. The SDDS has proved to be an effective means of destroying organic compounds in the gas phase, particularly dioxins, at temperatures as low as 150°C.
Formation of octachlorostyrene during the synthesis of chromium(iii) chloride
Mataruse,Yuknis,McDonald,Booth,Cleary,Twamley
, p. 69 - 74 (2002)
Octachlorostyrene has been recovered from the reaction tube, along with previously reported hexachlorobenzene, during the synthesis of CrCl3 from Cr2O3 and CCl4 at high temperature. The region in the reaction tube where the octachlorostyrene was found, namely upstream from the Cr2O3 held at 890°C, suggests that this molecule is formed at a temperature below 890°C and that it decomposes if raised to that temperature. A low gas flow was used in this experiment, allowing products to diffuse countercurrently. Copyright
FLUORINATION WITH POSITIVE FLUORINE GENERATED FROM ISOELECTRONICALLY RELATED REAGENTS
Cartwright, M.,Woolf, A. A.
, p. 101 - 122 (1982)
Compounds such as PhIF2, PhPF2 and XeF2, which have been used previously as unrelated fluorinating agents, are shown to be periodically related as isoelectronic molecules E3AF2 of trigonal-bipyramidal shape, where E represents a bonded or nonbonded electron pair and A a main Group V-VIII element.These compounds are arranged in order of halogenating ability by estimating the magnitude of reduction couples, approximated by ΔH0f(E3AF2-E3A), or by noting the direction of redox reactions involving the couples.The A sequence deduced Kr>Xe ca.Cl>Br>I>S>Se>Te-As-Sb>P agrees with the limited experimental data available.Evidence for an ionic mechanism involving 'onium' monohalide ions is given for halogenations with these reagents when carried out under "Friedel-Crafts" conditions although no stable salts containing these ions have as yet been isolated because of intramolecular halogenation.These ions act as sources of positive fluorine.The use of ring deactivated reagents to achieve halogenation is discussed.
Formation of octachloroacenaphthylene in the pyrolysis of decachlorobiphenyl
Bleise,Kleist,Guenther,Schwuger
, p. 655 - 666 (1997)
The pyrolytic degradation of decachlorobiphenyl (PCB 209) in the temperature range of 700-1000°C and at a pyrolysis time of 10 seconds generated one main chloroaromatic product. This compound has been identified by HPLC-UV, GC-MS, GC-FTIR and 13C-NMR as octachloroacenaphthylene (OCAN). The mechanism of the nearly quantitative formation of octachloroacenaphthylene (OCAN) occurs via a nonachlorobenzobarrylene radical (Z1R) as an intermediate followed by a rearrangement and further dechlorination to form OCAN. Calculations with the program THERM based on the Benson-group-theory indicated that this mechanism is not possible for lower or nonchlorinated biphenyls.
Synthesis of Decorated Carbon Structures with Encapsulated Components by Low-Voltage Electric Discharge Treatment
Bodrikov, I. V.,Pryakhina, V. I.,Titov, D. Yu.,Titov, E. Yu.,Vorotyntsev, A. V.
, p. 60 - 69 (2022/03/17)
Abstract: Polycondensation of complexes of chloromethanes with triphenylphosphine by the action of low-voltage electric discharges in the liquid phase gives nanosized solid products. The elemental composition involving the generation of element distribution maps (scanning electron microscopy–energy dispersive X?ray spectroscopy mapping) and the component composition (by direct evolved gas analysis–mass spectrometry) of the solid products have been studied. The elemental and component compositions of the result-ing structures vary widely depending on the chlorine content in the substrate and on the amount of triphenylphosphine taken. Thermal desorption analysis revealed abnormal behavior of HCl and benzene present in the solid products. In thermal desorption spectra, these components appear at an uncharacteristically high temperature. The observed anomaly in the behavior of HCl is due to HCl binding into a complex of the solid anion HCI-2 with triphenyl(chloromethyl)phosphonium chloride, which requires a relatively high temperature (up to 800 K) to decompose. The abnormal behavior of benzene is associated with its encapsulated state in nanostructures. The appearance of benzene begins at 650 K and continues up to temperatures above 1300?K.
Isomerization of perchlorohexatriene in three consecutive rearrangements to perchloro-2-vinylbutadiene
Schollmeyer, Dieter,Detert, Heiner
supporting information, p. 843 - 846 (2017/02/18)
Perchlorohexatriene isomerizes in three subsequent rearrangements to perchloro-2-vinylbutadiene. A radical-induced Z-E-equilibration of linear perchlorohexatrienes is followed by cyclization to a methylenecyclopentene. Under flash-vacuum pyrolysis conditions, a ring contraction to 1,2-dimethylenecyclobutane occurs. In the condensed phase, a radical-induced ring opening generates the branched perchloro-vinylbutadiene. All compounds are converted to hexachlorobenzene, but only at very high temperatures.
