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Chlorinated Products (chlorinated + products)
Selected AbstractsBank Security Dye Packs: Synthesis, Isolation, and Characterization of Chlorinated Products of Bleached 1-(methylamino)anthraquinoneJOURNAL OF FORENSIC SCIENCES, Issue 6 2006James M. Egan Ph.D. ABSTRACT: Banknote evidence is often submitted after a suspect has attempted to disguise or remove red dye stain that has been released because of an anti-theft device that activates after banknotes have been unlawfully removed from bank premises. Three chlorinated compounds have been synthesized as forensic chemical standards to indicate bank security dye bleaching as a suspect's intentional method for masking a robbery involving dye pack release on banknotes. A novel, facile synthetic method to provide three chlorinated derivatives of 1-(methylamino)anthraquinone (MAAQ) is presented. The synthetic route involved Ultra CloroxÔ bleach as the chlorine source, iron chloride as the catalyst, and MAAQ as the starting material and resulted in a three-component product mixture. Two mono-chlorinated isomers (2-chloro-1-(methylamino)anthraquinone and 4-chloro-1-(methylamino)anthraquinone) and one di-chlorinated compound (2,4-dichloro-1-(methylamino)anthraquinone) of the MAAQ parent molecule were detected by gas chromatography mass spectrometry (GC-MS), and subsequently isolated by liquid chromatography (LC) with postcolumn fraction collection. Although GC-MS is sensitive enough to detect all of the chlorinated products, it is not definitive enough to identify the structural isomers. Liquid-state nuclear magnetic resonance (NMR) spectroscopy was utilized to elucidate structurally the ortho- and para-mono-chlorinated isomers once enough material was properly isolated. A reaction mechanism involving iron is proposed to explain the presence of chlorinated MAAQ species on stolen banknotes after attempted bleaching. [source] Trichlorofluoroethene: A reactive tracer for evaluating reductive dechlorination in large-diameter permeable columnsGROUND WATER MONITORING & REMEDIATION, Issue 2 2005Jennifer A. Field Trichlorofluoroethene (TCFE) was used as a reactive tracer to determine the in situ rate of reductive dechlorination in treatment zones impacted by three large-diameter permeable columns (LDPCs) that were installed at a trichloroethene (TCE),contaminated site. The LDPCs were part of a pilot study to evaluate the effectiveness of hydrogen, lactate, and zero-valent iron for remediating TCE-contaminated ground water. The rate of TCFE reductive dechlorination was determined for each LDPC by means of push-pull tests conducted in each treatment layer. In addition, the distribution of TCFE's lesser chlorinated transformation products was determined. The rates of TCFE reductive dechlorination ranged from 0.05/d to 0.20/d and corresponded to half-lives ranging from 3.5 to 13.9 d. cis -Dichlorofluoroethene was the dominant transformation product detected in all the tests, which is consistent with the findings from pilot tests conducted in the LDPCs prior to the TCFE push-pull tests. cis -Chlorofluoroethene (CFE) and 1,1-CFE also were detected and indicate the potential for vinyl chloride to form under all treatment regimes. Significant production of fluoroethene (FE), the analog of ethene, was observed for only one of the hydrogen treatments. Unambiguous and sensitive detection of the lesser chlorinated products, such as CFE and FE, is possible because TCFE and its transformation products are not found in the background ground water at contaminated sites. Good agreement between the rates and transformation product profiles for TCFE and TCE in both field and laboratory experiments indicates the suitability of TCFE as a surrogate for predicting the rates of TCE reductive dechlorination. [source] Bank Security Dye Packs: Synthesis, Isolation, and Characterization of Chlorinated Products of Bleached 1-(methylamino)anthraquinoneJOURNAL OF FORENSIC SCIENCES, Issue 6 2006James M. Egan Ph.D. ABSTRACT: Banknote evidence is often submitted after a suspect has attempted to disguise or remove red dye stain that has been released because of an anti-theft device that activates after banknotes have been unlawfully removed from bank premises. Three chlorinated compounds have been synthesized as forensic chemical standards to indicate bank security dye bleaching as a suspect's intentional method for masking a robbery involving dye pack release on banknotes. A novel, facile synthetic method to provide three chlorinated derivatives of 1-(methylamino)anthraquinone (MAAQ) is presented. The synthetic route involved Ultra CloroxÔ bleach as the chlorine source, iron chloride as the catalyst, and MAAQ as the starting material and resulted in a three-component product mixture. Two mono-chlorinated isomers (2-chloro-1-(methylamino)anthraquinone and 4-chloro-1-(methylamino)anthraquinone) and one di-chlorinated compound (2,4-dichloro-1-(methylamino)anthraquinone) of the MAAQ parent molecule were detected by gas chromatography mass spectrometry (GC-MS), and subsequently isolated by liquid chromatography (LC) with postcolumn fraction collection. Although GC-MS is sensitive enough to detect all of the chlorinated products, it is not definitive enough to identify the structural isomers. Liquid-state nuclear magnetic resonance (NMR) spectroscopy was utilized to elucidate structurally the ortho- and para-mono-chlorinated isomers once enough material was properly isolated. A reaction mechanism involving iron is proposed to explain the presence of chlorinated MAAQ species on stolen banknotes after attempted bleaching. [source] Catalytic Asymmetric Bromination and Chlorination of ,-KetoestersCHEMISTRY - A EUROPEAN JOURNAL, Issue 9 2004Mauro Marigo Abstract The first general catalytic asymmetric bromination and chlorination of ,-ketoesters has been developed. The reactions proceed for both acyclic and cyclic ,-ketoesters catalyzed by chiral bisoxazolinecopper(II) complexes giving the corresponding optically active ,-bromo- and ,-chloro-,-ketoesters in high yields and moderate to good enantioselectivities. For the optically active chlorinated products the isolated yields are in the range of 88,99,% and the enantiomeric excesses up to 77,% ee, while the optically active brominated adducts are formed in 70,99,% isolated yield and up to 82,% ee. Based on the absolute configuration of the optically active products, the face selectivity for the catalytic enantioselective halogenation is discussed based on a bidentate coordination of the ,-ketoester to the chiral catalyst and a X-ray structure of chiral ,,,-diketoesterenolatebisoxazolinecopper(II) complex. [source] | ||||||||||