A straightforward protocol using readily available aromatic amines,N,N,N',N'-tetramethyl-p-phenylenediamine or N,N,N',N'-tetramethylbenzidine,as photocatalysts was developed for theefficient hydrodehal...A straightforward protocol using readily available aromatic amines,N,N,N',N'-tetramethyl-p-phenylenediamine or N,N,N',N'-tetramethylbenzidine,as photocatalysts was developed for theefficient hydrodehalogenation of organic halides,such as 4'-bromoacetophenone,polyfluoroarenes,cholorobenzene,and 2,2',4,4'-tetrabromodiphenyl ether(a resistant and persistent organic pollu-tant).The strongly reducing singlet excited states of the amines enabled diffusion-controlled disso-ciative electron transfer to effectively cleave carbon-halogen bonds,followed by radical hydrogena-tion.Diisopropylethylamine served as the terminal electron/proton donor and regenerated theamine sensitizers.展开更多
In the present work,bimetallic silver/zinc was applied into the degradation of trihalomethanes,THMs:CHCl_(3),CHBrCl_(2),CHBr_(2)Cl,and CHBr_(3).The kinetics reaction rates and removal efficiencies of the THM compound ...In the present work,bimetallic silver/zinc was applied into the degradation of trihalomethanes,THMs:CHCl_(3),CHBrCl_(2),CHBr_(2)Cl,and CHBr_(3).The kinetics reaction rates and removal efficiencies of the THM compound mixtures,in the aqueous solutions,were investigated.Batch experiments were conducted under mild conditions,ambient temperature,and pressure.The primary degradation reaction followed a pseudo-first-order kinetic law.The first-order rate constants and the degradation efficiencies followed the decreasing order of CHBr_(3)>CHBr_(2)Cl>CHBrCl_(2)>CHCl_(3).The bond dissociation energy and hydrophilic/hydrophobic characteristics of the THM compounds may become the most important parameters affecting the degradation kinetics and efficiency by bimetallic Ag/Zn.展开更多
文摘A straightforward protocol using readily available aromatic amines,N,N,N',N'-tetramethyl-p-phenylenediamine or N,N,N',N'-tetramethylbenzidine,as photocatalysts was developed for theefficient hydrodehalogenation of organic halides,such as 4'-bromoacetophenone,polyfluoroarenes,cholorobenzene,and 2,2',4,4'-tetrabromodiphenyl ether(a resistant and persistent organic pollu-tant).The strongly reducing singlet excited states of the amines enabled diffusion-controlled disso-ciative electron transfer to effectively cleave carbon-halogen bonds,followed by radical hydrogena-tion.Diisopropylethylamine served as the terminal electron/proton donor and regenerated theamine sensitizers.
基金partially supported by the Ministry of Education,Culture,Sports,Science,and Technology of Japan.
文摘In the present work,bimetallic silver/zinc was applied into the degradation of trihalomethanes,THMs:CHCl_(3),CHBrCl_(2),CHBr_(2)Cl,and CHBr_(3).The kinetics reaction rates and removal efficiencies of the THM compound mixtures,in the aqueous solutions,were investigated.Batch experiments were conducted under mild conditions,ambient temperature,and pressure.The primary degradation reaction followed a pseudo-first-order kinetic law.The first-order rate constants and the degradation efficiencies followed the decreasing order of CHBr_(3)>CHBr_(2)Cl>CHBrCl_(2)>CHCl_(3).The bond dissociation energy and hydrophilic/hydrophobic characteristics of the THM compounds may become the most important parameters affecting the degradation kinetics and efficiency by bimetallic Ag/Zn.
