The photo-induced vapor-phase decomposition of dimethyl ether was investigated on Pt metals deposited on pure and N-doped TiO2. Infrared spectroscopic measurements revealed that adsorption of dimethyl ether on TiO2 sa...The photo-induced vapor-phase decomposition of dimethyl ether was investigated on Pt metals deposited on pure and N-doped TiO2. Infrared spectroscopic measurements revealed that adsorption of dimethyl ether on TiO2 samples underwent partial dissociation to methoxy species. Illumination of the (CH3)2O-TiO2 and (CH3)2O-M/TiO2 systems led to the conversion of methoxy into adsorbed formate. In the case of metal-promoted TiO2 catalysts, CO bonded to the metals was also detected. Pure titania exhibited a very little photoactivity. Deposition of Pt metals on TiO2 markedly enhanced the extent of photocatalytic decomposition of dimethyl ether to give H2 and CO2 as the major products. A small amount of CO and methyl formate was also identified in the products. The most active metal was the Rh followed by Pd, Ir, Pt and Ru. When the bandgap of TiO2 was lowered by N-doping, the photocatalytic activity of metal/TiO2 catalysts appreciably increased. The effect of metals was explained by a better separation of charge carriers induced by illumination and by enhanced electronic interaction between metal nanoparticles and TiO2.展开更多
The growth, biochemical content and bioaccumulation quantity of 2,2',4,4'-tetrabromodiphenyl ether(BDE-47) in Skeletonema costatum were studied under different N:P ratios(1, 4, 16, 64 and 128). All cellular bi...The growth, biochemical content and bioaccumulation quantity of 2,2',4,4'-tetrabromodiphenyl ether(BDE-47) in Skeletonema costatum were studied under different N:P ratios(1, 4, 16, 64 and 128). All cellular biochemical contents of S. costatum presented decreasing trend over cultivation time. At early stage of cultivation, the cellular protein, carbohydrate and lipid in S. costatum presented higher values in treatments of N:P=4 and 16. However, they were lower in these treatments at the late stage, but higher in treatments N:P=1 and 128. Similarly, BDE-47 levels per cell of S. costatum were higher in treatments of N:P=4 and 16 at early stage of cultivation, which were 3.8 and 3.7 ng(106 cells)-1, respectively. At the middle stage of cultivation, the BDE-47 level per S. costatum cell lowered; and it further reduced in the treatments of N:P=4 and 16 at the late stage with the values 0.6 and 0.5 ng(106 cells)-1, respectively. However, it rose in N:P=128, reaching up to 2.3 ng(106 cells)-1. Compared with BDE-47 per cell, BDE-47 per algal volume under different N:P ratios did not present obvious difference. The quantity BDE-47 accumulated per cell of S. costatum was positively correlated with protein, carbohydrate and lipid per cell; meanwhile, the BDE-47 per volume had a positive correlation with biochemical content per volume. The variation of bioaccumulation ability of BDE-47 in S. costatum can be explained by biochemical changes due to N:P ratios.展开更多
Five novel bis—(N—alkyl—N,N—dimethyl ammoni(?)n)polyethyleneglyool ether salts prepared by our previously reported proced(?)e show high catalytic efficiency in the condensation of 1,4—diacetyl— 2,5—piperazinedi...Five novel bis—(N—alkyl—N,N—dimethyl ammoni(?)n)polyethyleneglyool ether salts prepared by our previously reported proced(?)e show high catalytic efficiency in the condensation of 1,4—diacetyl— 2,5—piperazinedione and aldehydes at both higher and lower temperature even in lower concentration.They al so show catalytic selectivity at lower temperature.展开更多
Bis diphenyl 22 and 11 Membered Ring N pivot lariat Crown Ethers were prepared by one step reaction of 2,2' dihydroxy diphenyl with N tosyl diethanolamine ditoskylate in DMF at refluxing tem perature unde...Bis diphenyl 22 and 11 Membered Ring N pivot lariat Crown Ethers were prepared by one step reaction of 2,2' dihydroxy diphenyl with N tosyl diethanolamine ditoskylate in DMF at refluxing tem perature under N z,Using anhydrous potassium carbonate as condensing agent,respectirely.The tosyl group of(1,2) were removed by treatment with 40%HBr in AcoH in the presence gf a large amount of phenol to give correspondence crown ether compounds(3,4).New N pirot lariat crown thers(5,6)were prepared by one step reaction of(3)with RBr(R=-CH 2CH=CH 2,-CH 2(CH 2) 14 CH 3) in CH 3CN at refluxing temperature under N 2,Using anhydrous K 2CO 3 as condensing agent.New N pivot lariat croon ether(7) were prepared by one step reaction (4)with n bromohexadecane in CH 3CN at refluxing temperature under N 2, Using anhydrous potassium carbonate as condensing agent.New compounds(1,3,5,6,7)were characterized by IR,, 1H NMR,Ms and elemental analysis.展开更多
The N--N linkage in hydrazine is thermally stable when it is tetrasubstituted and there are electron-withdrawinggroups attached to the nitrogen atoms. Our research on the synthesis of polymers contaning N--N linkages ...The N--N linkage in hydrazine is thermally stable when it is tetrasubstituted and there are electron-withdrawinggroups attached to the nitrogen atoms. Our research on the synthesis of polymers contaning N--N linkages is reviewed. TheN,N-bisimide structure has been introduced in the backbone of polymers as well as a pendant group in poly(aryl ether)s togive very thermoxidatively stable polymers with very high glass transition temperatures. Most of the polymers form tough,flexible films. N-Aminotriazoles also form stable imides by reaction with anhydrides and these N-imidotriazole groups havebeen introduced as pendent groups on poly(aryl ether)s. The polymers are highly fluorescent materials. Three methods for thesynthesis of polymers containing the tetrasubstituted-azine structure will be discussed: (1) oxidative coupling of bisimines;(2) condensation of bishydrazones with diketones; (3) poly(aryl ether azines) from the azine formed from 4-fluorobenzo-phenone by reaction with salts of bisphenols.展开更多
A highly efficient and selective[2+2+2]cyclization of diynes and monoalkynes was catalyzed by rhodium under room temperature in water/THF mixed solvent,affording isoindolines and isobenzofurans in good to excellent yi...A highly efficient and selective[2+2+2]cyclization of diynes and monoalkynes was catalyzed by rhodium under room temperature in water/THF mixed solvent,affording isoindolines and isobenzofurans in good to excellent yields.The center atoms (N,O) in the diynes showed a significant effect for the cyclization.展开更多
(R)-N-(β-Trichlorogermyl propionyl)thiazolidine-2-thione-4-carboxylic methyl ether(1) and its sesquioxide(2) were synthesized. The crystal structure of 1 was determined by means of X-ray diffraction analysis, which s...(R)-N-(β-Trichlorogermyl propionyl)thiazolidine-2-thione-4-carboxylic methyl ether(1) and its sesquioxide(2) were synthesized. The crystal structure of 1 was determined by means of X-ray diffraction analysis, which shown that the >CO and >CS groups are located in the opposite sides of C(4)—N—C(3) bond with transconfiguration. The electronic structures and optimized configurations of compounds 1 and 2 were studied with MNDO method.展开更多
NaBH<sub>4</sub>, CH<sub>3</sub>CO<sub>2</sub>H, Pd/C has been described as an effective reagent system to hydrogenate alkenes. Here, we show that the hydrogenation occurs chemosele...NaBH<sub>4</sub>, CH<sub>3</sub>CO<sub>2</sub>H, Pd/C has been described as an effective reagent system to hydrogenate alkenes. Here, we show that the hydrogenation occurs chemoselectively, making it possible to hydrogenate alkenes under Pd/C catalysis with hydrogen created in situ without O- or N-debenzylation.展开更多
A series of ternary complexes of rare earth(Ⅲ)nitrate with benzo-15-crown-5 and 4-picoline N-oxide have been prepared.They have the general formula of RE(NO_3)_3·2(4-picNO)·3H_2O·(1/2)(B-15-C-5) (RE=La...A series of ternary complexes of rare earth(Ⅲ)nitrate with benzo-15-crown-5 and 4-picoline N-oxide have been prepared.They have the general formula of RE(NO_3)_3·2(4-picNO)·3H_2O·(1/2)(B-15-C-5) (RE=La～Tm).Their physico-chemical properties have also been studied with conductance,thermal analysis and IR absorption spectroscopy.展开更多
The aggregating properties of Cz-C-n (n = 3, 6, 10) have been investigated by means of fluorescence method in DMSO-H2O binary solvent. The measured CAC and C F values indicate that the aggregating tendency of the amp...The aggregating properties of Cz-C-n (n = 3, 6, 10) have been investigated by means of fluorescence method in DMSO-H2O binary solvent. The measured CAC and C F values indicate that the aggregating tendency of the amphiphilic compounds Cz-C-n containing crown ether increases with the length of alkyl chains, similar to that of carbazole compounds with long alkyl chains.展开更多
文摘The photo-induced vapor-phase decomposition of dimethyl ether was investigated on Pt metals deposited on pure and N-doped TiO2. Infrared spectroscopic measurements revealed that adsorption of dimethyl ether on TiO2 samples underwent partial dissociation to methoxy species. Illumination of the (CH3)2O-TiO2 and (CH3)2O-M/TiO2 systems led to the conversion of methoxy into adsorbed formate. In the case of metal-promoted TiO2 catalysts, CO bonded to the metals was also detected. Pure titania exhibited a very little photoactivity. Deposition of Pt metals on TiO2 markedly enhanced the extent of photocatalytic decomposition of dimethyl ether to give H2 and CO2 as the major products. A small amount of CO and methyl formate was also identified in the products. The most active metal was the Rh followed by Pd, Ir, Pt and Ru. When the bandgap of TiO2 was lowered by N-doping, the photocatalytic activity of metal/TiO2 catalysts appreciably increased. The effect of metals was explained by a better separation of charge carriers induced by illumination and by enhanced electronic interaction between metal nanoparticles and TiO2.
基金supported by the National Natural Science Foundation of China (No. 40906061)the Science and Technology Plan Projects of Qingdao (No. 12-1-364-nsh)+1 种基金the ‘Two Districts’ Foundation of Shandong Province, China (No. 2011-Yellow-19)the Talent Foundation of Qingdao Agricultural University (No. 630642)
文摘The growth, biochemical content and bioaccumulation quantity of 2,2',4,4'-tetrabromodiphenyl ether(BDE-47) in Skeletonema costatum were studied under different N:P ratios(1, 4, 16, 64 and 128). All cellular biochemical contents of S. costatum presented decreasing trend over cultivation time. At early stage of cultivation, the cellular protein, carbohydrate and lipid in S. costatum presented higher values in treatments of N:P=4 and 16. However, they were lower in these treatments at the late stage, but higher in treatments N:P=1 and 128. Similarly, BDE-47 levels per cell of S. costatum were higher in treatments of N:P=4 and 16 at early stage of cultivation, which were 3.8 and 3.7 ng(106 cells)-1, respectively. At the middle stage of cultivation, the BDE-47 level per S. costatum cell lowered; and it further reduced in the treatments of N:P=4 and 16 at the late stage with the values 0.6 and 0.5 ng(106 cells)-1, respectively. However, it rose in N:P=128, reaching up to 2.3 ng(106 cells)-1. Compared with BDE-47 per cell, BDE-47 per algal volume under different N:P ratios did not present obvious difference. The quantity BDE-47 accumulated per cell of S. costatum was positively correlated with protein, carbohydrate and lipid per cell; meanwhile, the BDE-47 per volume had a positive correlation with biochemical content per volume. The variation of bioaccumulation ability of BDE-47 in S. costatum can be explained by biochemical changes due to N:P ratios.
文摘Five novel bis—(N—alkyl—N,N—dimethyl ammoni(?)n)polyethyleneglyool ether salts prepared by our previously reported proced(?)e show high catalytic efficiency in the condensation of 1,4—diacetyl— 2,5—piperazinedione and aldehydes at both higher and lower temperature even in lower concentration.They al so show catalytic selectivity at lower temperature.
文摘Bis diphenyl 22 and 11 Membered Ring N pivot lariat Crown Ethers were prepared by one step reaction of 2,2' dihydroxy diphenyl with N tosyl diethanolamine ditoskylate in DMF at refluxing tem perature under N z,Using anhydrous potassium carbonate as condensing agent,respectirely.The tosyl group of(1,2) were removed by treatment with 40%HBr in AcoH in the presence gf a large amount of phenol to give correspondence crown ether compounds(3,4).New N pirot lariat crown thers(5,6)were prepared by one step reaction of(3)with RBr(R=-CH 2CH=CH 2,-CH 2(CH 2) 14 CH 3) in CH 3CN at refluxing temperature under N 2,Using anhydrous K 2CO 3 as condensing agent.New N pivot lariat croon ether(7) were prepared by one step reaction (4)with n bromohexadecane in CH 3CN at refluxing temperature under N 2, Using anhydrous potassium carbonate as condensing agent.New compounds(1,3,5,6,7)were characterized by IR,, 1H NMR,Ms and elemental analysis.
文摘The N--N linkage in hydrazine is thermally stable when it is tetrasubstituted and there are electron-withdrawinggroups attached to the nitrogen atoms. Our research on the synthesis of polymers contaning N--N linkages is reviewed. TheN,N-bisimide structure has been introduced in the backbone of polymers as well as a pendant group in poly(aryl ether)s togive very thermoxidatively stable polymers with very high glass transition temperatures. Most of the polymers form tough,flexible films. N-Aminotriazoles also form stable imides by reaction with anhydrides and these N-imidotriazole groups havebeen introduced as pendent groups on poly(aryl ether)s. The polymers are highly fluorescent materials. Three methods for thesynthesis of polymers containing the tetrasubstituted-azine structure will be discussed: (1) oxidative coupling of bisimines;(2) condensation of bishydrazones with diketones; (3) poly(aryl ether azines) from the azine formed from 4-fluorobenzo-phenone by reaction with salts of bisphenols.
文摘A highly efficient and selective[2+2+2]cyclization of diynes and monoalkynes was catalyzed by rhodium under room temperature in water/THF mixed solvent,affording isoindolines and isobenzofurans in good to excellent yields.The center atoms (N,O) in the diynes showed a significant effect for the cyclization.
文摘(R)-N-(β-Trichlorogermyl propionyl)thiazolidine-2-thione-4-carboxylic methyl ether(1) and its sesquioxide(2) were synthesized. The crystal structure of 1 was determined by means of X-ray diffraction analysis, which shown that the >CO and >CS groups are located in the opposite sides of C(4)—N—C(3) bond with transconfiguration. The electronic structures and optimized configurations of compounds 1 and 2 were studied with MNDO method.
文摘NaBH<sub>4</sub>, CH<sub>3</sub>CO<sub>2</sub>H, Pd/C has been described as an effective reagent system to hydrogenate alkenes. Here, we show that the hydrogenation occurs chemoselectively, making it possible to hydrogenate alkenes under Pd/C catalysis with hydrogen created in situ without O- or N-debenzylation.
文摘A series of ternary complexes of rare earth(Ⅲ)nitrate with benzo-15-crown-5 and 4-picoline N-oxide have been prepared.They have the general formula of RE(NO_3)_3·2(4-picNO)·3H_2O·(1/2)(B-15-C-5) (RE=La～Tm).Their physico-chemical properties have also been studied with conductance,thermal analysis and IR absorption spectroscopy.
基金We thank the National Natural Science Foundation of China. The foundation of the Ministry of Science and Technology of China (grant No. G2000078104 and No. G2000077502) for financial supports.
文摘The aggregating properties of Cz-C-n (n = 3, 6, 10) have been investigated by means of fluorescence method in DMSO-H2O binary solvent. The measured CAC and C F values indicate that the aggregating tendency of the amphiphilic compounds Cz-C-n containing crown ether increases with the length of alkyl chains, similar to that of carbazole compounds with long alkyl chains.
