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 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
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
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 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.
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.
