Synthesis of 3,3＇,4,4＇-tetrahydro-4,4＇-bibenzo[e][1,3]oxazine-2,2＇-diones via reaction of salicylidendphenylhy- drazone and triphosgene with the aid of low-valent titanium reagent is described. This method has the...Synthesis of 3,3＇,4,4＇-tetrahydro-4,4＇-bibenzo[e][1,3]oxazine-2,2＇-diones via reaction of salicylidendphenylhy- drazone and triphosgene with the aid of low-valent titanium reagent is described. This method has the advantages of accessible starting materials, good yields and short reaction time.展开更多
This paper focuses on the pathway,the kinetic laws and the mechanisms of BDE-47 photo-degradation in the environment.By changing the degradation conditions(such as light sources,solvents,inorganic salts and free radic...This paper focuses on the pathway,the kinetic laws and the mechanisms of BDE-47 photo-degradation in the environment.By changing the degradation conditions(such as light sources,solvents,inorganic salts and free radical scavengers)and analyzing the degradation products using gas chromatography(GC)and gas chromatography/mass spectrometry(GC/MS),a better understanding of the fate of 2,2',4,4'-Tetrabromodiphenyl ether(BDE-47)in the environment is obtained.Results show that(i)the degradation reactions of BDE-47 under four different types of light sources are well described by the first order kinetic equation(r≥0.9995);(ii)hydrogen-donating ability and light absorption property of an organic solvent have a joint influence on the kinetics of degradation of BDE-47,which makes the degradation rate constants of BDE-47 different in different solvents(hexane 0.2735,methanol 0.2720,toluene 0.1280,methanol/water(1:1)0.0673,acetonitrile 0.0471,acetone 0.0030);(iii)the types and quantities of detected degradation products of BDE-47 are different in different solvents,BDE-1 is found only in hexane solvent,BDE-3 is not found in toluene,the relative content of BDE-28 in toluene is the highest(91.3%);(iv)inorganic ions have different effects on the degradation of BDE-47,the half-life of 0.10 mmol Fe^(3+) is reduced by 46.1%compared with that without adding 0.10 mmol Fe^(3+),the half-life of 0.5 mmol NH_(4)^(+) is reduced by 46.7%compared with that without 0.5 mmol NH4 t,50 mg/L TBA can increase the halflife by 5.1%compared with no addition.展开更多
基金Project supported by the National Natural Science Foundation of China （No. 21072144） and the Major Basic Research Project of the Natural Science Foundation of the Jiangsu Higher Education Institutions （No. 10KJAI50049）.
文摘Synthesis of 3,3＇,4,4＇-tetrahydro-4,4＇-bibenzo[e][1,3]oxazine-2,2＇-diones via reaction of salicylidendphenylhy- drazone and triphosgene with the aid of low-valent titanium reagent is described. This method has the advantages of accessible starting materials, good yields and short reaction time.
基金This work is supported by the National Natural Science Foundation of China(No.21377033),and the Key Program of Hebei Education Department(No.ZD20131046).
文摘This paper focuses on the pathway,the kinetic laws and the mechanisms of BDE-47 photo-degradation in the environment.By changing the degradation conditions(such as light sources,solvents,inorganic salts and free radical scavengers)and analyzing the degradation products using gas chromatography(GC)and gas chromatography/mass spectrometry(GC/MS),a better understanding of the fate of 2,2',4,4'-Tetrabromodiphenyl ether(BDE-47)in the environment is obtained.Results show that(i)the degradation reactions of BDE-47 under four different types of light sources are well described by the first order kinetic equation(r≥0.9995);(ii)hydrogen-donating ability and light absorption property of an organic solvent have a joint influence on the kinetics of degradation of BDE-47,which makes the degradation rate constants of BDE-47 different in different solvents(hexane 0.2735,methanol 0.2720,toluene 0.1280,methanol/water(1:1)0.0673,acetonitrile 0.0471,acetone 0.0030);(iii)the types and quantities of detected degradation products of BDE-47 are different in different solvents,BDE-1 is found only in hexane solvent,BDE-3 is not found in toluene,the relative content of BDE-28 in toluene is the highest(91.3%);(iv)inorganic ions have different effects on the degradation of BDE-47,the half-life of 0.10 mmol Fe^(3+) is reduced by 46.1%compared with that without adding 0.10 mmol Fe^(3+),the half-life of 0.5 mmol NH_(4)^(+) is reduced by 46.7%compared with that without 0.5 mmol NH4 t,50 mg/L TBA can increase the halflife by 5.1%compared with no addition.
