58-90-2

Usage

Uses

Used in Wood Preservation Industry:
2,3,4,6-Tetrachlorophenol is used as a wood preservative for its ability to protect against decay and infestation by insects and fungi, thereby extending the lifespan and durability of wooden materials.
Used in Fungicide Applications:
In the agricultural sector, 2,3,4,6-Tetrachlorophenol serves as a fungicide, helping to control fungal growth on crops and prevent diseases that can lead to reduced yields and quality of produce.
Despite its applications, it is crucial to note that due to the compound's high toxicity and environmental persistence, its use is heavily regulated to minimize potential harmful effects on both human health and the environment. Alternative, less harmful substances are often sought for these applications to mitigate the risks associated with 2,3,4,6-Tetrachlorophenol.

InChI:InChI=1/C6H2Cl4O/c7-2-1-3(8)6(11)5(10)4(2)9/h1,11H

Upstream product

• 583-78-8 2,5-dichlorophenol 
• 7462-04-6 2,3,4,4,5,6,6-heptachloro-cyclohex-2-enone 
• 40932-60-3 3,5,6-Trichloro-2-hydroxybenzoic acid 
• 704892-44-4 2,3,4,6-tetrachloro-5-hydroxy-benzaldehyde 
• 139-02-6 sodium phenoxide 
• 88-06-2 2,4,6-Trichlorophenol 
• 108-95-2 phenol 
• 87-86-5 Pentachlorophenol 
• 608-93-5 pentachlorobenzene 
• 25108-10-5 2,3,4,6,6-pentachloro-2,4-cyclohexadienone 
• 131-52-2 sodium pentachlorphenate 
• 95-57-8 2-monochlorophenol 
• 7686-32-0 6-hydroxy-1,2,3-benzothiadiazole 
• 64-19-7 acetic acid 

Downstream Products

• 5435-60-9 2,3,4,6-tetrachlorophenyl acetate 
• 56818-02-1 2,3,4,6-tetrachloro-phenetole 
• 24003-12-1 benzoic acid-(2,3,4,6-tetrachloro-phenyl ester) 
• 855394-24-0 (2-bromo-ethyl)-(2,3,4,6-tetrachloro-phenyl)-ether 
• 51661-18-8 1,2-bis-(2,3,4,6-tetrachloro-phenoxy)-ethane 
• 10587-37-8 (2,3,4,6-tetrachloro-phenoxy)-acetic acid 
• 100125-37-9 benzenesulfonic acid-(2,3,4,6-tetrachloro-phenyl ester) 
• 100541-32-0 1-(2,4-dichloro-phenoxy)-2-(2,3,4,6-tetrachloro-phenoxy)-ethane 
• 100540-57-6 1-(2,3,4,6-tetrachloro-phenoxy)-2-(2,4,6-trichloro-phenoxy)-ethane 
• 64673-08-1 2-(2,3,4,6-tetrachloro-phenoxy)-ethanol 
• 18967-29-8 methacrylic acid-(2,3,4,6-tetrachloro-phenyl ester) 
• 938-22-7 2,3,4,6-tetrachloroanisole 
• 634-85-5 2,3,6-trichloro-1,4-benzoquinone 
• 51685-65-5 2,3,4,4,6-pentachloro-2,5-cyclohexadienone 

Relevant academic research and scientific papers

Photocatalytic degradation of lindane by polyoxometalates: Intermediates and mechanistic aspects

The photocatalytic degradation of lindane (γ-1,2,3,4,5,6-hexachlorocyclohexane) has been studied in the presence of the polyoxometalate PW12O403- in aqueous solutions. Lindane is fully decomposed to CO2, Cl- and H2O, while a great variety of intermediates has been detected using GC-MS, including aromatic compounds (dichlorophenol, trichlorophenols, tetrachlorophenol, hexachlorobenzene, di- and trichloro-benzenodiol), non-aromatic cyclic compounds (penta-, tetrachlorocyclohexene, heptachlorocyclohexane), aliphatic compounds (tetrachloroethane) and condensation products (polychlorinated biphenyls). The number and nature of the intermediates implies that the mechanism of decomposition of lindane is based on both oxidative and reductive processes. Common intermediates have been reported during photolysis of lindane in the presence of titanium dioxide. A similar overall mechanism of polyoxometalates and TiO2 photocatalysis through the formation of common reactive species is suggested.

Formation of chlorinated phenols, dibenzo-p-dioxins, dibenzofurans, benzenes, benzoquinnones and perchloroethylenes from phenols in oxidative and copper (II) chloride-catalyzed thermal process

Formation of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and chlorinated phenols on CuCl2 from unsubstituted phenol and three monochlorophenols was studied in a flow reactor over a temperature range of 100-425 °C. Heated nitrogen gas streams containing 8.0% oxygen were used as carrier gas. The 0.00024 mol of unsubstituted phenol and 0.00039 mol of each monochlorophenol were passed through a 1 g and 1 cm SiO2 particle containing 0.5% (Cu by mass) CuCl2. Chlorination preferentially occurred on ortho-(2, 6) and para-(4) positions. Chlorination increased up to 200 °C, and thereafter decreased as temperature increased. Chlorination of phenols plays an important role in the formation of the more chlorinated PCDD/Fs. Chlorinated benzenes are formed possibly from both chlorination of benzene and chlorodehydroxylation of phenols. Chlorinated phenols with ortho chlorine formed PCDD products, and major PCDD products were produced via loss of one chlorine. For PCDF formation, at least one unchlorinated ortho carbon was required.

Method for reducing microcontaminants during synthesis of pentachlorophenol

A method for reducing contaminants during synthesis of pentachlorophenol includes providing a phenol-based starting material and a catalyst, which form a reaction mixture. A chlorine flow is introduced so that it is in contact with the reaction mixture, and the starting material and chlorine are reacted via a temperature-programmed reaction. The chlorine flow is terminated at a predetermined temperature prior to an end of the temperature-programmed reaction and/or at a point where the yield of pentachlorophenol is less than about 95%.

Electroreduction of Organic Compounds, 34 [1]. Cathodic Dehalogenation of Chloroarenes with Electron-Donating Substituents

The electrochemical reduction of chlorinated arenes with electron-donating substituents, i.e. chlorotoluenes, -anisoles and -phenols, is studied. Preparative electrolyses are run in various solvent-supporting electrolytes under potentiostatic and galvanostatic conditions at lead or carbon cathodes. A partial and mostly regioselective hydrodechlorination of compounds with two or more chloro substituents is possible under suitable conditions. The replacement of one single chloro substituent, in particular in a para-position, is difficult. Highly toxic and persistent oligochloro derivatives are thus transformed into less problematic compounds with a low degree of chlorination. The chlorine content of real-life materials such as extracts of soil contaminated with chlorinated phenols and Nitrofen can also be significantly decreased by electroreduction.

Identification of surrogate compounds for the emission of PCDD/F (I-TEQ value) and evaluation of their on-line realtime detectability in flue gases of waste incineration plants by REMPI-TOFMS mass spectrometry

Correlations between products of incomplete combustion (PIC), e.g., chloroaromatic compounds, can be used to characterise the emissions from combustion processes, like municipal or hazardous waste incineration. A possible application of such relationships may be the on-line real-time monitoring of a characteristic surrogate, e.g., with Resonance-Enhanced Multiphoton Ionization-Time-of-Flight Mass Spectrometry (REMPI-TOFMS). In this paper, we report the relationships of homologues and individual congeners of chlorinated benzenes (PCBz), dibenzo-p-dioxins (PCDD), dibenzofurans (PCDF) and phenols (PCPh) to the International Toxicity Equivalent (I-TEQ) of the PCDD/F (I-TEQ value) in the flue gas and stack gas of a 22 MW hazardous waste incinerator (HWI). As the REMPI detection sensitivity is decreasing with the increase of the degree of chlorination, this study focuses on the lower chlorinated species of the compounds mentioned above. Lower chlorinated species, e.g., chlorobenzene (MCBz), 1,4-dichlorobenzene, 2,4,6-trichlorodibenzofuran or 2,4-dichlorophenol, were identified as I-TEQ surrogates in the flue gas. In contrast to the higher chlorinated phenols, the lower chlorinated phenols (degree of chlorination 4) were not reliable as surrogates in the stack gas. The identified surrogates are evaluated in terms of their detectability by REMPI-TOFMS laser mass spectrometry. The outcome is that MCBz is the best suited surrogate for (indirect) on-line measuring of the I-TEQ value in the flue gas by REMPI-TOFMS. The correlation coefficient r of the MCBz concentration to the I-TEQ in the flue gas was 0.85.

Reactions of 2,4,6-trichlorophenol on model fly ash: Oxidation to CO and CO2, condensation to PCDD/F and conversion into related compounds

Thermal treatment of 2,4,6-trichlorophenol on a magnesium silicate-based model fly ash in the temperature range between 250°C and 400°C leads predominantly to carbon monoxide and carbon dioxide. The fraction of 2,4,6-trichlorophenol which is oxidized to CO and CO2 increases from 3% at 250°C to 75% at 400°C. Further products are polychlorinated benzenes, dibenzo-p-dioxins, dibenzofurans and phenols. The homologue and isomer patterns of the chlorobenzenes suggest chlorination in the ipso-position of the trichlorophenol. The formation of PCDD from 2,4,6-trichlorophenol and 2,3,4,6-tetrachlorophenol on municipal solid waste incinerator fly ashes and model fly ash were compared and the reaction order calculated.

Dechlorination of pentachlorophenol by zero valent iron and modified zero valent irons

The disappearance of pentachlorophenol (PCP) from aqueous solutions in contact with zero valent metals (ZVMs) may be due to dechlorination reactions or sorption to ZVM-related surfaces. Previously reported results on PCP and zero valent iron measured only PCP loss from aqueous solutions and attributed this loss to reaction. In this study, the total amount of unreacted PCP, both that in aqueous solution and that sorbed to ZVM-related surfaces, was measured using a modified extraction method. PCP dechlorination was confirmed by following the appearance of tetrachlorophenol isomers. The results indicate that the rate of dechlorination is much slower than previously reported. In our experiments, electrolytic zero valent iron with a surface area of 0.12 m2/g resulted in an observed first-order rate constant (±95% confidence limits) of 3.9 (±0.7) x 10-3 h-1 or a half-life of approximately 7.4 days. Normalized to surface area, the rate constant (k(SA)) is 3.2 (±0.6) x 10-4 L m-2 h-1. Four amended irons prepared by coating iron with palladium (Pd/Fe), platinum (Pt/Fe), nickel (Ni/Fe), and copper (Cu/Fe) were also used and showed slower removal rates as compared to unamended iron (estimated half-lives of 36-43 days). Slower reaction rates obtained with amended irons as compared to iron have not been previously reported. Overall, this study conclusively demonstrates PCP dechlorination by iron and several bimetallic ZVMs and indicates that it is essential to separate reaction and sorption processes. The disappearance of pentachlorophenol (PCP) from aqueous solutions in contact with zero valent metals (ZVMs) may be due to dechlorination reactions or sorption to ZVM-related surfaces. Previously reported results on PCP and zero valent iron measured only PCP loss from aqueous solutions and attributed this loss to reaction. In this study, the total amount of unreacted PCP, both that in aqueous solution and that sorbed to ZVM-related surfaces, was measured using a modified extraction method. PCP dechlorination was confirmed by following the appearance of tetrachlorophenol isomers. The results indicate that the rate of dechlorination is much slower than previously reported. In our experiments, electrolytic zero valent iron with a surface area of 0.12 m2/g resulted in an observed first-order rate constant (±95% confidence limits) of 3.9 (±0.7) × 10-3 h-1 or a half-life of approximately 7.4 days. Normalized to surface area, the rate constant (kSA) is 3.2 (±0.6) × 10-4 L m-2 h-1. Four amended irons prepared by coating iron with palladium (Pd/Fe), platinum (Pt/Fe), nickel (Ni/Fe), and copper (Cu/Fe) were also used and showed slower removal rates as compared to unamended iron (estimated half-lives of 36-43 days). Slower reaction rates obtained with amended irons as compared to iron have not been previously reported. Overall, this study conclusively demonstrates PCP dechlorination by iron and several bimetallic ZVMs and indicates that it is essential to separate reaction and sorption processes.

Natural formation of chlorinated phenols, dibenzo-p-dioxins, and dibenzofurans in soil of a Douglas fir forest

The natural formation of 4-MCP, 24/25- and 26-DCP, and 245-TrCP was detected in four selected areas of a rural Douglas fir forest where the humic layer was spiked in situ with a solution of Na37Cl and covered by an enclosure, after 1 year of incubation. Chlorinated phenols (CP) can be formed naturally from organic matter and inorganic chloride by either de novo synthesis or chloroperoxidase (CPO)-catalyzed chlorination. The natural CP congeners were found to be present in high concentrations in soil compared to the other congeners, except for 245-TrCP which was present in a relatively low concentration. This study did not reveal which source, natural or anthropogenic, caused the observed concentrations. Some 20 chlorinated dibenzo-p-dioxins and dibenzofurans (CDD/F) were found to be formed naturally in soil of the Douglas fir forest; the formation of three 2,3,7,8-substituted congeners, 2378-TeCDD, 12378-PeCDD, and 123789-HxCDD, deserves special attention. A formation mechanism has been proposed which starts from naturally formed CP congeners and which probably involves peroxidase mediation. Chlorination of CDD/F congeners by the CPO-mediated reaction cannot be ruled out, but seems to be less likely due to the absence of several predicted congeners. The natural formation of 4-MCP, 24/25- and 26-DCP, and 245-TrCP was detected in four selected areas of a rural Douglas fir forest where the humic layer was spiked in situ with a solution of Na37Cl and covered by an enclosure, after 1 year of incubation. Chlorinated phenols (CP) can be formed naturally from organic matter and inorganic chloride by either de novo synthesis or chloroperoxidase (CPO)-catalyzed chlorination. The natural CP congeners were found to be present in high concentrations in soil compared to the other congeners, except for 245-TrCP which was present in a relatively low concentration. This study did not reveal which source, natural or anthropogenic, caused the observed concentrations. Some 20 chlorinated dibenzo-p-dioxins and dibenzofurans (CDD/F) were found to be formed naturally in soil of the Douglas fir forest; the formation of three 2,3,7,8-substituted congeners, 2378-TeCDD, 12378-PeCDD, and 123789-HxCDD, deserves special attention. A formation mechanism has been proposed which starts from naturally formed CP congeners and which probably involves peroxidase mediation. Chlorination of CDD/F congeners by the CPO-mediated reaction cannot be ruled out, but seems to be less likely due to the absence of several predicted congeners.

Rate enhancement by cations in supercritical water oxidation of 2- chlorophenol

Interactions between cations and Cl species in the supercritical water oxidation (SCWO) of 2.-chlorophenol (2CP) has been investigated in a high- pressure quartz-lined reactor at 673-773 K. Experimentally, we found that the S/D ratio (defined as the amount of 2CP converted to CO2 and H2O/disappearance of 2CP) for SCWO of 2CP was enhanced by cations (such as Li+, Na+, K+, Ca2+, Fe2+, or Fe3+). The S/D ratio increased as the charge density of cations increased (Fe3+> Fe2+ > Li+ > Ca2+ > Na+ > K+). Due to the extremely low solubility of metal salts in the supercritical water, abstraction of Cl in 2CP via an intermediate ((OH)PhCl(δ-)---- M(δ+) was postulated. Formation of these metal chloride (such as KCl, CaCl2, and FeCl3) precipitates in the SCWO of 2CP were identified by X-ray diffraction (XRD) spectroscopy. Since the formation of toxic highly chlorinated phenols and heavy polycyclic aromatic hydrocarbons (PAHs) was notably reduced, abstraction of Cl of 2CP by cations may occur in the early stage of the SCWO process. Interactions between cations and Cl species in the supercritical water oxidation (SCWO) of 2-chlorophenol (2CP) has been investigated in a high-pressure quartz-lined reactor at 673-773 K. Experimentally, we found that the S/D ratio (defined as the amount of 2CP converted to CO2 and H2O/disappearance of 2CP) for SCWO of 2CP was enhanced by cations (such as Li+, Na+, K+, Ca2+, Fe2+, or Fe3+). The S/D ratio increased as the charge density of cations increased (Fe3+>Fe2+>Li+>Ca2+ >Na+>K+). Due to the extremely low solubility of metal salts in the supercritical water, abstraction of Cl in 2CP via an intermediate ((OH)PhClδ-- - - - -Mδ+) was postulated. Formation of these metal chloride (such as KCl, CaCl2, and FeCl3) precipitates in the SCWO of 2CP were identified by X-ray diffraction (XRD) spectroscopy. Since the formation of toxic highly chlorinated phenols and heavy polycyclic aromatic hydrocarbons (PAHs) was notably reduced, abstraction of Cl of 2CP by cations may occur in the early stage of the SCWO process.

Toxicity changes during the UV treatment of pentachlorophenol in dilute aqueous solution

Pentachlorophenol (PCP) was photolysed using a 1 kW photochemical reactor. The degradation of PCP (0.15 mM) was carried out using both direct UV photolysis and photolysis in the presence of H2O2 (3.0, 6.7, 18.0 and 37.2 mM). The decay of PCP and the formation of photoproducts were followed by high performance liquid chromatography, ion chromatography and UV absorbance detection. The first-order rate constants k1 for the decay of PCP were estimated under various conditions: for direct UV photolysis, k1 = 0.115 min-1; for photolysis in the presence of various concentrations of H2O2, the rate constant increased to a plateau (k1 ? 0.7 min-1) at H2O2 concentrations greater than 6 mM. The correlation between photodegradation and toxicity was studied using a bacterial toxicity test and a 96 h Fathead Minnow toxicity test. In both cases, the toxicity decreased as the concentration of PCP or the total organic chlorine concentration fell. These results indicate that the UV treatment of PCP either does not generate significant levels of acutely toxic intermediates, or any toxic intermediates are rapidly degraded under the specific conditions used in these studies. Pentachlorophenol (PCP) was photolysed using a 1 kW photochemical reactor. The degradation of PCP (0.15 mM) was carried out using both direct UV photolysis and photolysis in the presence of H2O2 (3.0, 6.7, 18.0 and 37.2 mM). The decay of PCP and the formation of photoproducts were followed by high performance liquid chromatography, ion chromatography and UV absorbance detection. The first-order rate constants k1 for the decay of PCP were estimated under various conditions: for direct UV photolysis, k1 = 0.115 min-1; for photolysis in the presence of various concentrations of H2O2, the rate constant increased to a plateau (k1≈0.7 min-1) at H2O2 concentrations greater than 6 mM. The correlation between photodegradation and toxicity was studied using a bacterial toxicity test and a 96 h Fathead Minnow toxicity test. In both cases, the toxicity decreased as the concentration of PCP or the total organic chlorine concentration fell. These results indicate that the UV treatment of PCP either does not generate significant levels of acutely toxic intermediates, or any toxic intermediates are rapidly degraded under the specific conditions used in these studies.