79-43-6Relevant articles and documents
Photocatalytic degradation of dichloroacetyl chloride adsorbed on TiO 2
Nishikiori, Hiromasa,Tagahara, Makoto,Mukoyama, Leo,Fujii, Tsuneo
, p. 947 - 957 (2010)
Dichloroacetyl chloride (DCAC) attracted our attention as an intermediate product of the photocatalytic degradation of trichloroethylene (TCE). The adsorption and photocatalytic reaction of DCAC on TiO2 have been investigated by FTIR spectroscopy. The influence of the surface structure of several TiO2s on the reaction mechanism was discussed in order to understand the complete degradation mechanism of TCE as well as DCAC. DCAC was transformed into dichloroacetic acid (DCAA) on the relatively hydrophobic TiO2 surface by the small amount of the water molecules weakly adsorbed on the surface. This DCAA was degraded to phosgene, CO2, and CO during UV irradiation. For the hydrophilic TiO2, DCAC was mainly transformed into the dichloroacetate anion. UV irradiation allowed this species to produce chloroform in addition to phosgene, CO2, and CO. It is suggested that DCAC easily reacts with the Ti-OH group on the hydrophilic TiO2 and forms the bidentate titanium chelate of dichloroacetate, which efficiently degrades into chloroform.
Correlation of molecular and morphologic effects of thermoembolization in a swine model using mass spectrometry imaging
Guo, Chunxiao,Baluya, Dodge L.,Thompson, Emily A.,Whitley, Elizabeth M.,Cressman, Erik N.K.
, (2020)
Hepatocellular carcinoma is a growing worldwide problem with a high mortality rate. This malignancy does not respond well to chemotherapy, and most patients present late in their disease at which time surgery is no longer an option. Over the past three decades, minimally invasive methods have evolved to treat unresectable disease and prolong survival. Intra-arterial embolization techniques are used for large or multiple tumors but have distressingly high levels of local recurrence and can be costly to implement. A new method called thermoembolization was recently reported, which destroys target tissue by combining reactive exothermic chemistry with an extreme local change in pH and ischemia. Described herein are experiments performed using this technique in vivo in a swine model. A microcatheter was advanced under fluoroscopic guidance into a branch of the hepatic artery to deliver a targeted dose of dichloroacetyl chloride dissolved in ethiodized oil into the liver. The following day, the animals were imaged by computed tomography and euthanized. Assessing the reaction product distribution and establishing a correlation with the effects are important for understanding the effects. This presented a significant challenge, however, as the reagent used does not contain a chromophore and is not otherwise readily detectable. Mass spectrometry imaging was employed to determine spatial distribution in treated samples. Additional insights on the biology were obtained by correlating the results with histology, immunohistochemistry, and immunofluorescence. The results are encouraging and may lead to a therapy with less local recurrence and improved overall survival for patients with this disease.
TiO2 MEDIATED PHOTOOXIDATION OF TRICHLOROETHYLENE AND TOLUENE DISSOLVED IN FLUOROCARBON SOLVENTS
Sun, Yunfu,Brown, Gilbert M.,Moyer, Bruce A.
, p. 3575 - 3584 (1995)
Titanium dioxide mediated photodegradation of trichloroethylene (TCE) and toluene dissolved in a fluorocarbon solvent (Galden HT110) was demonstrated. The photodegradation of TCE yielded dichloroacetic acid as a major intermediate. The TCE reaction kinetics and high photoefficiency suggest autocatalysis and/or a radical chain reaction mechanism. Photooxidation of toluene is a first-order reaction. Membrane-assisted solvent extraction of TCE from water to the fluorocarbon solvent was demonstrated, and the combination of photooxidation and extraction from the basis for a novel two-stage process for the removal and destruction of organic contaminants from water.
A Straightforward Homologation of Carbon Dioxide with Magnesium Carbenoids en Route to α-Halocarboxylic Acids
Monticelli, Serena,Urban, Ernst,Langer, Thierry,Holzer, Wolfgang,Pace, Vittorio
supporting information, p. 1001 - 1006 (2019/01/30)
The homologation of carbon dioxide with stable, (enantiopure) magnesium carbenoids constitutes a valuable method for preparing α-halo acid derivatives. The tactic features a high level of chemocontrol, thus enabling the synthesis of variously functionalized analogues. The flexibility to generate magnesium carbenoids through sulfoxide-, halogen- or proton- Mg exchange accounts for the wide scope of the reaction. (Figure presented.).
Effect of dissolved oxygen concentration on iron efficiency: Removal of three chloroacetic acids
Tang, Shun,Wang, Xiao-mao,Mao, Yu-qin,Zhao, Yu,Yang, Hong-wei,Xie, Yuefeng F.
, p. 342 - 352 (2015/03/04)
The monochloroacetic, dichloroacetic and trichloroacetic acid (MCAA, DCAA and TCAA) removed by metallic iron under controlled dissolved oxygen conditions (0, 0.75, 1.52, 2.59, 3.47 or 7.09mg/L DO) was investigated in well-mixed batch systems. The removal of CAAs increased first and then decreased with increasing DO concentration. Compared with anoxic condition, the reduction of MCAA and DCAA was substantially enhanced in the presence of O2, while TCAA reduction was significantly inhibited above 2.59mg/L. The 1.52mg/L DO was optimum for the formation of final product, acetic acid. Chlorine mass balances were 69-102%, and carbon mass balances were 92-105%. With sufficient mass transfer from bulk to the particle surface, the degradation of CAAs was limited by their reduction or migration rate within iron particles, which were dependent on the change of reducing agents and corrosion coatings. Under anoxic conditions, the reduction of CAAs was mainly inhibited by the available reducing agents in the conductive layer. Under low oxic conditions, the increasing reducing agents and thin lepidocrocite layer were favorable for CAA dechlorination. Under high oxic conditions, the redundant oxygen competing for reducing agents and significant lepidocrocite growth became the major restricting factors. Various CAA removal mechanisms could be potentially applied to explaining the effect of DO concentration on iron efficiency for contaminant reduction in water and wastewater treatment.