2474-72-8Relevant academic research and scientific papers
Phototransformation of resorcinol induced by excitation of nitrite and nitrate ions. II: nitrate ions
Machado,Boule
, p. 165 - 173 (1994)
The excitation of nitrate ions in an aqueous solution of resorcinol (I) at pH = 5.5-6.5, leads to a mixture of 1,2,3-trihydroxybenzene (II), 1,2,4-trihydroxybenzene (III), 4-nitrosoresorcinol (V) and 4-nitroresorcinol (VII). A secondary formation of 2, 4-dinitrosoresorcinol (VI) was also detected.
Catalytic mechanism of 5-chlorohydroxyhydroquinone dehydrochlorinase from the YCII superfamily of largely unknown function
Hayes, Robert P.,Lewis, Kevin M.,Xun, Luying,Kang, Chul Hee
, p. 28447 - 28456 (2013)
Background:TftG is a YCII superfamily dehydrochlorinase that catalyzes conversion of 5-chlorohydroxyhydroquinone to hydroxybenzoquinone. Results:The TftG crystal structure in complex with product analog 2,5-dihydroxybenzoquinone illustrated the catalytic residues and mechanism. Conclusion:A His-Asp dyad and other conserved signature residues are implicated for catalysis and substrate binding. Significance:This is the first elucidation of a YCII superfamily protein mechanism, which helps explain their obscure nature.
Kinetic studies of hydroxyquinone formation from water soluble benzoquinones
Jozsa, Eva,Purgel, Mihaly,Bihari, Marianna,Feher, Peter Pal,Sustyak, Gabor,Varnagy, Balazs,Kiss, Virag,Lado, Eszter,Osz, Katalin
, p. 588 - 597 (2014)
The kinetics and mechanisms of the redox reactions between hydrogen peroxide and 1,4-benzoquinone, 2-methyl-1,4-benzoquinone, 2,6-dimethyl-1,4- benzoquinone, 2-chloro-1,4-benzoquinone and 2,6-dichloro-1,4-benzoquinone were studied in aqueous media using spectrophotometric monitoring. The formation and decay of a hydroxylated 1,4-benzoquinone was detected. The formation of the intermediate was first order with respect to the parent 1,4-benzoquinone and hydrogen peroxide, whereas inverse first order dependence was revealed with respect to the hydrogen ion. The decomposition reaction had two parallel pathways: one was first order with respect to the intermediate, while the other showed second-order dependence. The values of the rate constant measured for the formation step were successfully correlated with both the redox potentials of the substituted quinone-hydroquinone systems and the pKa values of the hydroxylated quinone derivatives. Therefore, electronic effects govern the reactivity of the quinones in this process. NMR and GC-MS measurements were carried out to identify the products in the system. Quantum mechanical calculations were also carried out in these systems.
Synthesis, photochemical properties, and cytotoxicity of 10-alkylphenazin-2(10H)-ones
Kohatsu, Haruki,Kamo, Shogo,Hosokai, Takuya,Kamisuki, Shinji,Machida, Yutaro,Kobayashi, Ryota,Kawasaki, Tsuneomi,Ohgane, Kenji,Kuramochi, Kouji
, p. 871 - 885 (2021/05/19)
In the present study, the synthesis of a variety of 10-alkylphenazin-2(10H)-ones by oxidative coupling between N-alkylbenzene-1,2-diamine and 1,2,4-benzenetriol under an oxygen atmosphere was realized, and their photochemical and biological properties wer
Two-Dimensional Layered Zinc Silicate Nanosheets with Excellent Photocatalytic Performance for Organic Pollutant Degradation and CO2 Conversion
Wang, Lan,Bahnemann, Detlef W.,Bian, Liang,Dong, Guohui,Zhao, Jie,Wang, Chuanyi
supporting information, p. 8103 - 8108 (2019/05/22)
Two-dimensional (2D) photocatalysts are highly attractive for their great potential in environmental remediation and energy conversion. Herein, we report a novel layered zinc silicate (LZS) photocatalyst synthesized by a liquid-phase epitaxial growth route using silica derived from vermiculite, a layered silicate clay mineral, as both the lattice-matched substrate and Si source. The epitaxial growth of LZS is limited in the 2D directions, thus generating the vermiculite-type crystal structure and ultrathin nanosheet morphology with thicknesses of 8–15 nm and a lateral size of about 200 nm. Experimental observations and DFT calculations indicated that LZS has a superior band alignment for the degradation of organic pollutants and reduction of CO2 to CO. The material exhibited efficient photocatalytic performance for 4-chlorophenol (4-CP) degradation and CO2 conversion into CO and is the first example of a claylike 2D photocatalyst with strong photooxidation and photoreduction capabilities.
Significant effect of 5,10,15,20-meso-tetraarylporphyrinatoiron(III) chloride/triflate and acidic/neutral/basic imidazolium ionic liquids in catalytic oxidation of phenols
Ahmad, Sohail,Gautam, Renu,Singhal, Anchal,Chauhan
, p. 292 - 303 (2018/04/10)
The influence of acidic, neutral and basic ionic liquids and their binary mixture with dichloromethane on the reactivity of iron(III)porphyrins was investigated during oxidation of phenols with hydrogen peroxide catalysed by 5,10,15,20-tetraarylporphyrinatoiron(III) chloride and 5,10,15,20-tetraarylporphyrinatoiron(III) triflate. The generation of different intermediates of iron(III) porphyrin in different ILs was studied through viscosity, density, UV–Vis and 1H NMR spectroscopy. The heterolytic cleavage efficiency of (TAP)FeIII-OOH and formation of quinone using iron(III)porphyrin (TAP)FeIIICl with Cl atom as an axial ligand, is influenced by the structure of imidazolium moiety and the counteranion following the order [(CH2)4SO3HMIm]CF3COO > [Hmim]CF3COO > [bmim]TFA ?? negligible amount in [bmim]CF3SO3, [Hmim]CF3SO3, [bmim]BF4, [bmim]PF6 and [bmim]Cl. On the other hand, the heterolytic cleavage efficiency of (TAP)FeIII-OOH with iron(III)porphyrin (TAP)FeIIICF3SO3 with triflate as an axial ligand, was found in the following order [(CH2)4SO3HMIm]CF3SO3 > [Hmim]CF3SO3 > [(CH2)4SO3HMIm]CF3COO > [Hmim]CF3COO > [bmim] CF3COO > [bmim]PF6 ≈ [bmim]BF4 ≈ [bmim]CF3SO3, while epoxidation and polymerization were mainly observed in basic and neutral ILs. The reactive intermediates formed by the reaction of monooxygen donors with (TAP)FeIIICl varied with ILs, as (TAP)+?FeIV = O intermediate was dominated in acidic ILs, while (TAP)FeIV = O was formed in neutral ILs and (TAP)FeIII-OO– was formed in basic ILs.
A combined experimental and computational investigation on the unusual molecular mechanism of the lossen rearrangement reaction activated by carcinogenic halogenated quinones
Shan, Guo-Qiang,Yu, Ao,Zhao, Chuan-Fang,Huang, Chun-Hua,Zhu, Ling-Yan,Zhu, Ben-Zhan
, p. 180 - 189 (2017/03/06)
The classic Lossen rearrangement is a wellknown reaction describing the transformation of an Oactivated hydroxamic acid into the corresponding isocyanate. In this study, we found that chlorinated benzoquinones (CnBQ) serve as a new class of agents for the activation of benzohydroxamic acid (BHA), leading to Lossen rearrangement. Compared to the classic one, this new kind of CnBQ-activated Lossen rearrangement has the following unique characteristics: (1) The stability of CnBQ-activated BHA intermediates was found to depend not only on the degree but also on the position of Cl-substitution on CnBQs, which can be divided into two subgroups. (2) It is the relative energy of the anionic CnBQ-BHA intermediates that determine the rate of this CnBQ-activated rearrangement, which is the rate-limiting step, and the Cl or H ortho to the reaction site at CnBQ is crucial for the stability of the anionic intermediates. (3) A pKa-activation energy correlation was observed, which can explain why the correlation exists between the rate of the rearrangement and the acidity of the conjugate acid of the anionic leaving group, the hydroxlated quinones. These findings may have broad implications for future research on halogenated quinoid carcinogens and hydroxamate biomedical agents.
Application of photoactive electrospun nanofiber materials with immobilized meso-tetraphenylporphyrin for parabens photodegradation
Gmurek,Bizukoj?,Mosinger,Ledakowicz
, p. 160 - 167 (2015/02/19)
The pollution of aqueous environment by trace amounts of anthropogenic chemical substances has a hazardous impact on regular development of plants and animals as well as on human health. The paper presents the results of studies on the heterogeneous degradation of butyl- and benzylparaben in aqueous solutions using photochemically catalyzed processes. Meso-tetraphenylporphyrin (TPP) was immobilized in the polyurethane nanofiber material by electro-spinning method. The xenon lamp was used as a simulated sunlight source. The influence of various process parameters on reaction rate was investigated. The reuse of the carrier with the immobilized photosensitizer was examined. The major role of the singlet oxygen (1Δg) during the photodegradation was proved by using sodium azide and radical scavengers. The adsorption isotherms of parabens onto nanofiber material were determined using BET model. The kinetic study showed that the heterogeneous photodegradation of parabens could be modeled using Langmuir-Hinshelwood model and rate constants have been reported. The reaction pathway for the photodegradation of parabens via 1Δg was proposed.
Layered silicate as an excellent partner of a TiO2 photocatalyst for efficient and selective green fine-chemical synthesis
Ide, Yusuke,Torii, Masato,Sano, Tsuneji
, p. 11784 - 11786 (2013/09/02)
When the partial oxidation of benzene to phenol, which is one of the most important reactions in chemical industry, was conducted using TiO2 in the presence of a phenol-philic adsorbent derived from a layered silicate, phenol was recovered in u
The influence of hydroquinone on tyrosinase kinetics
Stratford, Michael R.L.,Ramsden, Christopher A.,Riley, Patrick A.
experimental part, p. 4364 - 4370 (2012/08/28)
In vitro studies, using combined spectrophotometry and oximetry together with hplc/ms examination of the products of tyrosinase action demonstrate that hydroquinone is not a primary substrate for the enzyme but is vicariously oxidised by a redox exchange mechanism in the presence of either catechol, l-3,4-dihydroxyphenylalanine or 4-ethylphenol. Secondary addition products formed in the presence of hydroquinone are shown to stimulate, rather than inhibit, the kinetics of substrate oxidation.
