Xn:Harmful;
106-48-9Relevant articles and documents
Photodegradation of Azole Fungicide Triadimefon
Nag, Subir K.,Dureja, Prem
, p. 294 - 298 (1997)
To examine the photostability of the fungicide triadimefon [1-(4-chlorophenoxy)-3,3-dimethyl-1H-(1,2,4-triazol-1-yl)butan-2-one] in the field, model experiments with organic solvents were performed. Photolysis in methanol, hexane, and acetone resulted in considerable formation of 1-(4-chlorophenoxy)-3,3-dimethylbutan-2-one, 1-[(4-chlorophenoxy)methyl]-1H-1,2,4-triazole, 1H-(1,2,4-triazol-1-yl)-3,3-dimethylbutan-2-one, and 1-phenoxy-3,3-dimethyl-1H-(1,2,4-triazol-1-yl)butan-2-one. The rate of photodegradation in different solvents followed first-order rate kinetics with a significant correlation coefficient.
Regioselective chlorination of phenols in the presence of tetrahydrothiopyran derivatives
Smith, Keith,Williams, Des,El-Hiti, Gamal A.
, p. 529 - 538 (2019)
Four six-membered cyclic sulfides, namely tetrahydrothiopyran, 3-methyltetrahydrothiopyran, 4-methyltetrahydrothiopyran and 4,4-dimethyltetrahyrdrothiopyran have been used as moderators in chlorination reactions of various phenols with sulfuryl chloride in the presence of aluminum or ferric chloride. On chlorination of phenol, ortho-cresol and meta-cresol the para/ortho chlorination ratios and yields of the para-chloro isomers are higher than when no cyclic sulfide is used for all of the cyclic sulfides, but chlorination of meta-xylenol is less consistent, with some cyclic sulfides producing higher p/o ratios and others producing lower ratios than reactions having no sulfide present.
Gas-phase oxychlorination of benzene
Born, Jan G. P.,Wart, Hans W. A. van der,Mulder, Peter,Louw, Robert
, p. 262 - 270 (1993)
Homogeneous gas-phase oxychlorination of benzene has been examined in a flow system between 722 and 1174 K.Experiments were performed at atmospheric pressure with nitrogen as an inert carrier gas, containing about equal molar amounts of oxygen, HCl and benzene.Apart from chlorobenzene, substantial amounts of o- and p-chlorophenol are produced.Using benzonitrile rather than benzene, the three isomers of ClC6H4CN are formed in about equal amounts.These findings suggest as homolytic mechanism with aryl radicals as key indermediates.Thermokinetic analysis points to formation of chloro phenols via reaction of phenoxyl (formed from phenyl and oxygen) with HOCl.Chlorination, C6H6 -> C6H5Cl, is explained by reaction between phenyl radicals and HOCl.With increasing temperature (and therefore, oxygen consumption), slow combustion is replaced by pyrolysis as the major reaction channel.As a result, above ca. 1000 K, the production of chlorobenzene diminishes, ultimately being governed by the equilibrium: C6H6 + HCl C6H5Cl + H2.
Regiospecific Chlorination of Aromatic Substrates using Donor-Acceptor and Hydrogen Bonding Interactions
Guy, Alain,Lemaire, Marc,Guette, Jean-Paul
, p. 8 - 9 (1980)
The chlorination of aromatic substances has been achieved with good regioselectivity using 2,3,4,4,5,6-hexachlorocyclohexa-2,5-dien-1-one and 2,3,4,5,6,6-hexachlorocyclohexa-2,4-dien-1-one as chlorinating agents.
HIGH ORTHO-SELECTIVITY IN THE CHLORINATION OF PHENOLS WITH N-CHLORODIALKYLAMINES IN THE PRESENCE OF SILICA.
Smith, Keith,Butters, Michael,Nay, Barry
, p. 1319 - 1322 (1988)
Phenols are readily chlorinated by N-chlorodialkylamines in the presence of silica.Furthermore, this approach allows greater selectivity for mono:di and ortho: para chlorination than is possible with many other approaches.
Kinetics and mechanism of the reaction of α-phenoxypropanoic acids with sodium salt of N-chlorobenzene-sulphonamide: EDTA catalysis
Meenakshisundaram, Subbiah,Selvaraju
, p. 27 - 33 (2002)
EDTA smoothly catalyses the oxidation cum chlorination of some 17 α-phenoxypropanoic acids with sodium salt of N-chlorobenzenesulphonamide in acidic solution. A ternary intermediate can be envisaged for describing the enhanced reactivity. Imperfections are observed in the linear Hammett relationship in the case of-NO2 substituents, irrespective of the position. The susceptibility constant, p(≈ + 1) indicates the development of an electron-rich transition state.
Surface decorated coral-like magnetic BiFeO3 with Au nanoparticles for effective sunlight photodegradation of 2,4-D and E. coli inactivation
Lam, Sze-Mun,Jaffari, Zeeshan Haider,Sin, Jin-Chung,Zeng, Honghu,Lin, Hua,Li, Haixiang,Mohamed, Abdul Rahman,Ng, Ding-Quan
, (2021)
In this report, gold nanoparticle-decorated on the coral-like magnetic BiFeO3 (Au-BiFeO3) composite has been successfully fabricated by facile two-steps hydrothermal technique. Incorporation of Au nanoparticles on the BiFeO3/su
Hydroxylation of Benzene with Dinitrogen Monoxide over H-ZSM-5 Zeolite
Suzuki, Eiichi,Nakashiro, Katsumi,Ono, Yoshio
, p. 953 - 956 (1988)
Phenol was obtained from benzene and dinitrogen monoxide over H-ZSM-5-zeolite at 603 K, a phenol yield on a benzene basis being 8.1percent at partial pressures of benzene and dinitrogen monoxide of 6.9 kPa and 51 kpa, respectively.Neither CO nor CO2 was detected in the product.
Nanoscale Fe0particles for pentachlorophenol removal from aqueous solution: Temperature effect and particles transformation
Cheng, Rong,Zheng, Xiang,Liu, Peng,Wang, Jian-Long
, p. 6941 - 6949 (2014)
Pentachlorophenol (PCP), as an important contaminant which was toxic and intractable, has received extensive attention. In this paper, the temperature effect during the transformation of PCP using nanoscale Fe0particles was studied, and the transformation processes of PCP and iron particles was explained. The results revealed that the removal processes of PCP followed pseudo first-order kinetics. The scale of dechlorination to the transformation of PCP increased with the increase of temperature, though the transformation rate decreased after reacting for 2 h under the experimental condition. However, the initial apparent transformation rate constants were calculated to be 0.312-0.536 h-1at the temperature of 20-50°C, which showed an increase of transformation rate along with the increase of temperature. And the surface-area-normalized rate constants were calculated to be 9.50 × 10-3- 1.63 × 10-2L·h-1· m-2. The experimental activation energy was calculated to be 15.0 kJ · mol-1from these rate constants using Arrhenius equation. A phenomenon observed at 50°C indicated that more than one chlorine atom was removed from PCP and suggested β-elimination might be the major pathway for transformation. Sorption experiments showed that the sorption process on the surface of particles could be ignored in the kinetics and thermodynamics models. The changes of morphologies of nanoparticles before and after reaction indicated the transformation process of iron particles, and could be used to explain the changes of activity of nanoparticles. Magnetite (Fe3O4) and/or maghemite (Fe2O3) and lepidocrocite (γ-FeOOH) were corrosion products of iron. And along with the increase of temperature, the increased intensity of XRD peaks revealed the related a better crystallizing. Copyright
Atmospheric chemistry of the phenoxy radical, C6H5O(?): UV spectrum and kinetics of its reaction with NO, NO2, and O2
Platz,Nielsen,Wallington,Ball,Hurley,Straccia,Schneider,Sehested
, p. 7964 - 7974 (1998)
Pulse radiolysis and FT-IR smog chamber experiments were used to investigate the atmospheric fate of C6H5O(?) radicals. Pulse radiolysis experiments gave σ(C6H5O(?))235 nm = (3.82 ± 0.48) × 10-17 cm2 molecule-1, k(C6H5O(?) + NO) = (1.88 ± 0.16) × 10-12, and k(C6H5O(?) + NO2) = (2.08 ± 0.15) × 10-12 cm3 molecule-1 s-1 at 296 K in 1000 mbar of SF6 diluent. No discernible reaction of C6H5O(?) radicals with O2 was observed in smog chamber experiments, and we derive an upper limit of k(C6H5O(?) + O2) -21 cm3 molecule-1 s-1 at 296 K. These results imply that the atmospheric fate of phenoxy radicals in urban air masses is reaction with NOx. Density functional calculations and gas chromatography-mass spectrometry are used to identify 4-phenoxyphenol as the major product of the self-reaction of C6H5O(?) radicals. As part of this study, relative rate techniques were used to measure rate constants for reaction of Cl atoms with phenol [k(Cl + C6H5OH) = (1.93 ± 0.36) × 10-10], several chlorophenols [k(Cl + 2-chlorophenol) = (7.32 ± 1.30) × 10-12, k(Cl + 3-chlorophenol) = (1.56 ± 0.21) × 10-10, and k(Cl + 4-chlorophenol) = (2.37 ± 0.30) × 10-10], and benzoquinone [k(Cl + benzoquinone) = (1.94 ± 0.35) × 10-10], all in units of cm3 molecule-1 s-1. A reaction between molecular chlorine and C6H5OH to produce 2- and 4-chlorophenol in yields of (28 ± 3)% and (75 ± 4)% was observed. This reaction is probably heterogeneous in nature, and an upper limit of k(Cl2 + C6H5OH) ≤ 1.9 × 10-20 cm3 molecule-1 s-1 was established for the homogeneous component. These results are discussed with respect to the previous literature data and to the atmospheric chemistry of aromatic compounds.
