615-67-8Relevant articles and documents
Photochemistry of Semiconductor Particles. Part 4. - Effects of Surface Condition on the Photodegradation of 2,4-Dichlorophenol catalysed by TiO2 Suspensions
Zang, Ling,Liu, Chun-Yan,Ren, Xin-Min
, p. 917 - 924 (1995)
The photocatalysed degradation of 2,4-dichlorophenol (DCP) has been investigated in aqueous suspensions of TiO2.A possible reaction scheme has been proposed for the degradation, in which chlorobenzoquinone (CBQ) was detected as a predominant intermediate present in the reaction solution.Kinetic details for the degradation steps have been analysed based on the experimental results.The essential role of oxygen was considered to be the capturing of the photogenerated electron to form the oxidizing species, such as H2O2, HO2(.) and OH(.).In anaerobic conditions, the photodegradation rate was quite low even with the adsorbed Cu(2+) ion on the TiO2 powder as an alternative electron scavenger.This is due to the rapid indirect recombination of the photogenerated electron and hole, which is mediated by the short-circuiting reaction of Cu(2+).However, in aerobic conditions, oxygen takes up the photogenerated electron trapped at the adsorbed Cu(2+) ion to prevent it from recombining with the photogenerated hole.As a result, the hole has sufficient opportunity to participate in the oxidizing reactions.The degradation rate was dependent to some extent on the surface charge of the TiO2 particles.Positive charge always promotes the photodegradation, whereas negative change is detrimental.This was attributed to the effects of surface charge on the migration of electrons from the interior of the TiO2 particles to the surface.
Photochemical transformations of 2, 6-dichlorophenol and 2-chlorophenol with superoxide ions in the atmospheric aqueous phase
Dong, Linchang,Hu, Shuheng,Lu, Jun,Peng, Shuchuan,Zhu, Chengzhu,Zhu, Mengyu
, (2022/04/03)
The possible photochemical transformation pathways of chlorophenols (2, 6-dichlorophenol and 2-chlorophenol) with superoxide anion radical (O2·?) were studied by steady-state irradiation and 355 nm laser flash photolysis technique. O
Preparation method of sesamol
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Paragraph 0022; 0026; 0028-0029, (2021/11/21)
The invention belongs to the technical field of compound synthesis, and particularly relates to a preparation method of sesamol, which firstly prepares 2 -chloro -1, 4 -diphenol, and then 2 - chlorine -1, 4 -biphenol and sodium hydroxide in an aqueous solution to obtain the sesamol, namely 1 2, 1 2 4 - 4 -triphenol and dichloromethane. The invention provides a new method for preparing the sesame phenol, and the yield of the sesamol is remarkably improved.
Can Donor Ligands Make Pd(OAc)2a Stronger Oxidant? Access to Elusive Palladium(II) Reduction Potentials and Effects of Ancillary Ligands via Palladium(II)/Hydroquinone Redox Equilibria
Bruns, David L.,Musaev, Djamaladdin G.,Stahl, Shannon S.
supporting information, p. 19678 - 19688 (2020/12/18)
Palladium(II)-catalyzed oxidation reactions represent an important class of methods for selective modification and functionalization of organic molecules. This field has benefitted greatly from the discovery of ancillary ligands that expand the scope, reactivity, and selectivity in these reactions; however, ancillary ligands also commonly poison these reactions. The different influences of ligands in these reactions remain poorly understood. For example, over the 60-year history of this field, the PdII/0 redox potentials for catalytically relevant Pd complexes have never been determined. Here, we report the unexpected discovery of (L)PdII(OAc)2-mediated oxidation of hydroquinones, the microscopic reverse of quinone-mediated oxidation of Pd0 commonly employed in PdII-catalyzed oxidation reactions. Analysis of redox equilibria arising from the reaction of (L)Pd(OAc)2 and hydroquinones (L = bathocuproine, 4,5-diazafluoren-9-one), generating reduced (L)Pd species and benzoquinones, provides the basis for determination of (L)PdII(OAc)2 reduction potentials. Experimental results are complemented by density functional theory calculations to show how a series of nitrogen-based ligands modulate the (L)PdII(OAc)2 reduction potential, thereby tuning the ability of PdII to serve as an effective oxidant of organic molecules in catalytic reactions.