The Experts below are selected from a list of 252 Experts worldwide ranked by ideXlab platform
Masatoshi Morita - One of the best experts on this subject based on the ideXlab platform.
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Detoxification of hexachlorobenzene by dechlorination with potassium-sodium alloy.
Chemosphere, 2004Co-Authors: Kumiko Miyoshi, Takehiko Nishio, Akio Yasuhara, Masatoshi Morita, Takayuki ShibamotoAbstract:Abstract Dechlorination of hexachlorobenzene (HCB) was achieved by a liquid potassium–sodium (K–Na)-alloy. HCB in a cyclohexane/benzene solution (22 mmol/l, 4.67 g/l as chlorine) was dechlorinated by almost 100% after a 30-min Reaction, indicating high reactivity of K–Na alloy and high proton donating power of cyclohexane. Decreasing orders of chlorobenzenes identified after a 15-min Reaction, by amount were 1,2,3,4- > 1,2,3,5- > 1,2,4,5- for tetrachlorobenzenes, 1,2,4- > 1,2,3- > 1,3,5- for trichlorobenzenes, and 1,4- > 1,3- > 1,2- for dichlorobenzenes. It was hypothesized that once one chlorine atom in HCB was replaced with a proton, the adjacent chlorine atom to the proton tended to be replaced with another hydrogen atom. A total of 63 PCBs formed via the Wurtz–Fittig Reaction were identified as by-products in the sample after a 15-min Reaction. Among PCBs found, 2,3 ′ ,4 ′ ,5-tetrachlorobiphenyl, which was a product from 1,2,4-trichlorobenzene formed via the Wurtz–Fittig Reaction, was detected in relatively high concentration (48.9 nmol/ml). The sample obtained from a Reaction mixture after 30 min contained only 14 PCBs in trace amounts, indicating that the PCBs formed were also further dechlorinated by K–Na alloy. Non-chlorinated compounds––such as methylbenzene, dimethylbenzene, dimer of tetrahydrofuran, and dicyclohexyl (dimer of cyclohexane)––were also identified in the samples. A method using K–Na alloy developed in the present study dechlorinated satisfactorily HCB at room temperature.
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Dechlorination of hexachlorobiphenyl by using potassium-sodium alloy.
Chemosphere, 2000Co-Authors: Kumiko Miyoshi, Takehiko Nishio, Akio Yasuhara, Masatoshi MoritaAbstract:Abstract 2,2′,4,4′,5,5′-Hexachlorobiphenyl (HCB) was dechlorinated with potassium–sodium (K–Na) alloy under an inert gas atmosphere. Solvent effect was observed in the Reaction. Dechlorination yields in benzene and cyclohexane were 99.9998% and 99.99996%, respectively. The Reaction was exothermic and proceeded at room temperature. In benzene, trace amounts of polychlorinated biphenyls (PCBs) as products by stepwise dechlorination and polychlorinated quarterphenyls as product of Wurtz–Fittig Reaction were detected as Reaction intermediate. Reaction products were biphenyl, cyclohexylbenzene, and dicyclohexyl. In cyclohexane, there were no products of Wurtz–Fittig Reaction. Dechlorination at para-position preferred to that at ortho-position, judging from analysis of PCBs as intermediates of stepwise dechlorination.
Kumiko Miyoshi - One of the best experts on this subject based on the ideXlab platform.
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Detoxification of hexachlorobenzene by dechlorination with potassium-sodium alloy.
Chemosphere, 2004Co-Authors: Kumiko Miyoshi, Takehiko Nishio, Akio Yasuhara, Masatoshi Morita, Takayuki ShibamotoAbstract:Abstract Dechlorination of hexachlorobenzene (HCB) was achieved by a liquid potassium–sodium (K–Na)-alloy. HCB in a cyclohexane/benzene solution (22 mmol/l, 4.67 g/l as chlorine) was dechlorinated by almost 100% after a 30-min Reaction, indicating high reactivity of K–Na alloy and high proton donating power of cyclohexane. Decreasing orders of chlorobenzenes identified after a 15-min Reaction, by amount were 1,2,3,4- > 1,2,3,5- > 1,2,4,5- for tetrachlorobenzenes, 1,2,4- > 1,2,3- > 1,3,5- for trichlorobenzenes, and 1,4- > 1,3- > 1,2- for dichlorobenzenes. It was hypothesized that once one chlorine atom in HCB was replaced with a proton, the adjacent chlorine atom to the proton tended to be replaced with another hydrogen atom. A total of 63 PCBs formed via the Wurtz–Fittig Reaction were identified as by-products in the sample after a 15-min Reaction. Among PCBs found, 2,3 ′ ,4 ′ ,5-tetrachlorobiphenyl, which was a product from 1,2,4-trichlorobenzene formed via the Wurtz–Fittig Reaction, was detected in relatively high concentration (48.9 nmol/ml). The sample obtained from a Reaction mixture after 30 min contained only 14 PCBs in trace amounts, indicating that the PCBs formed were also further dechlorinated by K–Na alloy. Non-chlorinated compounds––such as methylbenzene, dimethylbenzene, dimer of tetrahydrofuran, and dicyclohexyl (dimer of cyclohexane)––were also identified in the samples. A method using K–Na alloy developed in the present study dechlorinated satisfactorily HCB at room temperature.
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Dechlorination of hexachlorobiphenyl by using potassium-sodium alloy.
Chemosphere, 2000Co-Authors: Kumiko Miyoshi, Takehiko Nishio, Akio Yasuhara, Masatoshi MoritaAbstract:Abstract 2,2′,4,4′,5,5′-Hexachlorobiphenyl (HCB) was dechlorinated with potassium–sodium (K–Na) alloy under an inert gas atmosphere. Solvent effect was observed in the Reaction. Dechlorination yields in benzene and cyclohexane were 99.9998% and 99.99996%, respectively. The Reaction was exothermic and proceeded at room temperature. In benzene, trace amounts of polychlorinated biphenyls (PCBs) as products by stepwise dechlorination and polychlorinated quarterphenyls as product of Wurtz–Fittig Reaction were detected as Reaction intermediate. Reaction products were biphenyl, cyclohexylbenzene, and dicyclohexyl. In cyclohexane, there were no products of Wurtz–Fittig Reaction. Dechlorination at para-position preferred to that at ortho-position, judging from analysis of PCBs as intermediates of stepwise dechlorination.
Takehiko Nishio - One of the best experts on this subject based on the ideXlab platform.
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Detoxification of hexachlorobenzene by dechlorination with potassium-sodium alloy.
Chemosphere, 2004Co-Authors: Kumiko Miyoshi, Takehiko Nishio, Akio Yasuhara, Masatoshi Morita, Takayuki ShibamotoAbstract:Abstract Dechlorination of hexachlorobenzene (HCB) was achieved by a liquid potassium–sodium (K–Na)-alloy. HCB in a cyclohexane/benzene solution (22 mmol/l, 4.67 g/l as chlorine) was dechlorinated by almost 100% after a 30-min Reaction, indicating high reactivity of K–Na alloy and high proton donating power of cyclohexane. Decreasing orders of chlorobenzenes identified after a 15-min Reaction, by amount were 1,2,3,4- > 1,2,3,5- > 1,2,4,5- for tetrachlorobenzenes, 1,2,4- > 1,2,3- > 1,3,5- for trichlorobenzenes, and 1,4- > 1,3- > 1,2- for dichlorobenzenes. It was hypothesized that once one chlorine atom in HCB was replaced with a proton, the adjacent chlorine atom to the proton tended to be replaced with another hydrogen atom. A total of 63 PCBs formed via the Wurtz–Fittig Reaction were identified as by-products in the sample after a 15-min Reaction. Among PCBs found, 2,3 ′ ,4 ′ ,5-tetrachlorobiphenyl, which was a product from 1,2,4-trichlorobenzene formed via the Wurtz–Fittig Reaction, was detected in relatively high concentration (48.9 nmol/ml). The sample obtained from a Reaction mixture after 30 min contained only 14 PCBs in trace amounts, indicating that the PCBs formed were also further dechlorinated by K–Na alloy. Non-chlorinated compounds––such as methylbenzene, dimethylbenzene, dimer of tetrahydrofuran, and dicyclohexyl (dimer of cyclohexane)––were also identified in the samples. A method using K–Na alloy developed in the present study dechlorinated satisfactorily HCB at room temperature.
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Dechlorination of hexachlorobiphenyl by using potassium-sodium alloy.
Chemosphere, 2000Co-Authors: Kumiko Miyoshi, Takehiko Nishio, Akio Yasuhara, Masatoshi MoritaAbstract:Abstract 2,2′,4,4′,5,5′-Hexachlorobiphenyl (HCB) was dechlorinated with potassium–sodium (K–Na) alloy under an inert gas atmosphere. Solvent effect was observed in the Reaction. Dechlorination yields in benzene and cyclohexane were 99.9998% and 99.99996%, respectively. The Reaction was exothermic and proceeded at room temperature. In benzene, trace amounts of polychlorinated biphenyls (PCBs) as products by stepwise dechlorination and polychlorinated quarterphenyls as product of Wurtz–Fittig Reaction were detected as Reaction intermediate. Reaction products were biphenyl, cyclohexylbenzene, and dicyclohexyl. In cyclohexane, there were no products of Wurtz–Fittig Reaction. Dechlorination at para-position preferred to that at ortho-position, judging from analysis of PCBs as intermediates of stepwise dechlorination.
Akio Yasuhara - One of the best experts on this subject based on the ideXlab platform.
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Detoxification of hexachlorobenzene by dechlorination with potassium-sodium alloy.
Chemosphere, 2004Co-Authors: Kumiko Miyoshi, Takehiko Nishio, Akio Yasuhara, Masatoshi Morita, Takayuki ShibamotoAbstract:Abstract Dechlorination of hexachlorobenzene (HCB) was achieved by a liquid potassium–sodium (K–Na)-alloy. HCB in a cyclohexane/benzene solution (22 mmol/l, 4.67 g/l as chlorine) was dechlorinated by almost 100% after a 30-min Reaction, indicating high reactivity of K–Na alloy and high proton donating power of cyclohexane. Decreasing orders of chlorobenzenes identified after a 15-min Reaction, by amount were 1,2,3,4- > 1,2,3,5- > 1,2,4,5- for tetrachlorobenzenes, 1,2,4- > 1,2,3- > 1,3,5- for trichlorobenzenes, and 1,4- > 1,3- > 1,2- for dichlorobenzenes. It was hypothesized that once one chlorine atom in HCB was replaced with a proton, the adjacent chlorine atom to the proton tended to be replaced with another hydrogen atom. A total of 63 PCBs formed via the Wurtz–Fittig Reaction were identified as by-products in the sample after a 15-min Reaction. Among PCBs found, 2,3 ′ ,4 ′ ,5-tetrachlorobiphenyl, which was a product from 1,2,4-trichlorobenzene formed via the Wurtz–Fittig Reaction, was detected in relatively high concentration (48.9 nmol/ml). The sample obtained from a Reaction mixture after 30 min contained only 14 PCBs in trace amounts, indicating that the PCBs formed were also further dechlorinated by K–Na alloy. Non-chlorinated compounds––such as methylbenzene, dimethylbenzene, dimer of tetrahydrofuran, and dicyclohexyl (dimer of cyclohexane)––were also identified in the samples. A method using K–Na alloy developed in the present study dechlorinated satisfactorily HCB at room temperature.
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Dechlorination of hexachlorobiphenyl by using potassium-sodium alloy.
Chemosphere, 2000Co-Authors: Kumiko Miyoshi, Takehiko Nishio, Akio Yasuhara, Masatoshi MoritaAbstract:Abstract 2,2′,4,4′,5,5′-Hexachlorobiphenyl (HCB) was dechlorinated with potassium–sodium (K–Na) alloy under an inert gas atmosphere. Solvent effect was observed in the Reaction. Dechlorination yields in benzene and cyclohexane were 99.9998% and 99.99996%, respectively. The Reaction was exothermic and proceeded at room temperature. In benzene, trace amounts of polychlorinated biphenyls (PCBs) as products by stepwise dechlorination and polychlorinated quarterphenyls as product of Wurtz–Fittig Reaction were detected as Reaction intermediate. Reaction products were biphenyl, cyclohexylbenzene, and dicyclohexyl. In cyclohexane, there were no products of Wurtz–Fittig Reaction. Dechlorination at para-position preferred to that at ortho-position, judging from analysis of PCBs as intermediates of stepwise dechlorination.
Takayuki Shibamoto - One of the best experts on this subject based on the ideXlab platform.
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Detoxification of hexachlorobenzene by dechlorination with potassium-sodium alloy.
Chemosphere, 2004Co-Authors: Kumiko Miyoshi, Takehiko Nishio, Akio Yasuhara, Masatoshi Morita, Takayuki ShibamotoAbstract:Abstract Dechlorination of hexachlorobenzene (HCB) was achieved by a liquid potassium–sodium (K–Na)-alloy. HCB in a cyclohexane/benzene solution (22 mmol/l, 4.67 g/l as chlorine) was dechlorinated by almost 100% after a 30-min Reaction, indicating high reactivity of K–Na alloy and high proton donating power of cyclohexane. Decreasing orders of chlorobenzenes identified after a 15-min Reaction, by amount were 1,2,3,4- > 1,2,3,5- > 1,2,4,5- for tetrachlorobenzenes, 1,2,4- > 1,2,3- > 1,3,5- for trichlorobenzenes, and 1,4- > 1,3- > 1,2- for dichlorobenzenes. It was hypothesized that once one chlorine atom in HCB was replaced with a proton, the adjacent chlorine atom to the proton tended to be replaced with another hydrogen atom. A total of 63 PCBs formed via the Wurtz–Fittig Reaction were identified as by-products in the sample after a 15-min Reaction. Among PCBs found, 2,3 ′ ,4 ′ ,5-tetrachlorobiphenyl, which was a product from 1,2,4-trichlorobenzene formed via the Wurtz–Fittig Reaction, was detected in relatively high concentration (48.9 nmol/ml). The sample obtained from a Reaction mixture after 30 min contained only 14 PCBs in trace amounts, indicating that the PCBs formed were also further dechlorinated by K–Na alloy. Non-chlorinated compounds––such as methylbenzene, dimethylbenzene, dimer of tetrahydrofuran, and dicyclohexyl (dimer of cyclohexane)––were also identified in the samples. A method using K–Na alloy developed in the present study dechlorinated satisfactorily HCB at room temperature.
