The synthesis of the novel host compound carrying two spirobenzopyran groups was described.Its structure was confirmed by（）1H NMR,IR and elemental analysis.It was shown that the novel host can recognize lanthanide i...The synthesis of the novel host compound carrying two spirobenzopyran groups was described.Its structure was confirmed by（）1H NMR,IR and elemental analysis.It was shown that the novel host can recognize lanthanide ions selectively with significant spectral shifts in visible region and enhanced absorbance.Thus,the compound can be used to recognize lanthanide ions by naked eyes. The selectivity was relative to size-fit effect.The order of spectral changes was Yb3+>Er3+>Gd3+>Dy3+>Eu3+>Pr3+>La3+,which is opposite to the order of the radii of lanthanide ions.We discussed the possible binding mechanism with analyzing the different UV-Vis spectral changes resulted by addition of the investigated ions.展开更多
Glassy carbon electrode modified by 25,27-dihydroxy-26,28-di（2’-Methyl-6-hydroxypyrimidine）thiopentaoxylcalix[4] arene-PVC was made.The electrochemical character of the modified electrode was investigated by Cyclic...Glassy carbon electrode modified by 25,27-dihydroxy-26,28-di（2’-Methyl-6-hydroxypyrimidine）thiopentaoxylcalix[4] arene-PVC was made.The electrochemical character of the modified electrode was investigated by Cyclic Votalmmetry in HCl,HNO3 and H2SO4.Effects of concentration of HCl and scan rate were discussed.The modified Glassy carbon electrode was found to be excellent respondence to Cd2+in 1mol/L HCl.The experiment parameters such as accumulation potential and time and scan rate were determined on Cadmium.It was found that the linear equation is Ip（μA）=10.95+2.430 lgc（mol/L）（r=0.9968）.The concentration is in the range from 5.0×10-3to 8.0×10-7mol/L and the detect limit is 8.0×10-7mol/L.The method has been applied to the analysis of synthetic sample.The recovery of Cd2+is 98%.展开更多
The luminescent behavior on formation 1∶1 complex of 25,26,27,28 tetra carboxylic acid 5,11,17,23 calixarenesulfonate(L 2) and terbium(Ⅲ) ion was investigated by means of fluorescence spectra. The results showed tha...The luminescent behavior on formation 1∶1 complex of 25,26,27,28 tetra carboxylic acid 5,11,17,23 calixarenesulfonate(L 2) and terbium(Ⅲ) ion was investigated by means of fluorescence spectra. The results showed that the pH value of the solution had obviousan influence on the fluorescence intensity of L 2·Tb 3+ complex, but the fluorescence intensity was hardly changed over the pH range from 6 to 11. The complex exhibits a higher emission quantum yield( φ =0.31) in aqueous solution, which indicates energy transfer type emission. The complexation behavior of L 2 with trivalent lanthanoid ions(Tb 3+ and Eu 3+ ) was also studied in aqueous boracic acid(hydrochloric acid buffer solution(pH 8.0) at 25 ℃ by UV Vis and fluorescence measurements. The spectrophotometric titrations have been performed to give the complex stability constants( K S) for the stoichiometric 1∶1 inclusion complexation of L 2 with Tb 3+ and Eu 3+ . The complex stability for L 2·Eu 3+ was higher than that for L 2·Tb 3+ , but no characteristic fluorescence was found.展开更多
The synthesis of new chromogenic p (o,m,p carboxylazo)Calixarenes derivatives through the couping of diazotized o,m,p aminobenzene carboxylic acid and calixarenes was described.Their structures were comfirmed by IR, 1...The synthesis of new chromogenic p (o,m,p carboxylazo)Calixarenes derivatives through the couping of diazotized o,m,p aminobenzene carboxylic acid and calixarenes was described.Their structures were comfirmed by IR, 1H NMR and elemental analysis.Their chromogenic properties and UV Vis absorption spectra were investigated under different pH conditions.Experimental results show that the synthesized derivatives can be used as new indicators and host展开更多
文摘The synthesis of the novel host compound carrying two spirobenzopyran groups was described.Its structure was confirmed by（）1H NMR,IR and elemental analysis.It was shown that the novel host can recognize lanthanide ions selectively with significant spectral shifts in visible region and enhanced absorbance.Thus,the compound can be used to recognize lanthanide ions by naked eyes. The selectivity was relative to size-fit effect.The order of spectral changes was Yb3+>Er3+>Gd3+>Dy3+>Eu3+>Pr3+>La3+,which is opposite to the order of the radii of lanthanide ions.We discussed the possible binding mechanism with analyzing the different UV-Vis spectral changes resulted by addition of the investigated ions.
文摘Glassy carbon electrode modified by 25,27-dihydroxy-26,28-di（2’-Methyl-6-hydroxypyrimidine）thiopentaoxylcalix[4] arene-PVC was made.The electrochemical character of the modified electrode was investigated by Cyclic Votalmmetry in HCl,HNO3 and H2SO4.Effects of concentration of HCl and scan rate were discussed.The modified Glassy carbon electrode was found to be excellent respondence to Cd2+in 1mol/L HCl.The experiment parameters such as accumulation potential and time and scan rate were determined on Cadmium.It was found that the linear equation is Ip（μA）=10.95+2.430 lgc（mol/L）（r=0.9968）.The concentration is in the range from 5.0×10-3to 8.0×10-7mol/L and the detect limit is 8.0×10-7mol/L.The method has been applied to the analysis of synthetic sample.The recovery of Cd2+is 98%.
文摘The luminescent behavior on formation 1∶1 complex of 25,26,27,28 tetra carboxylic acid 5,11,17,23 calixarenesulfonate(L 2) and terbium(Ⅲ) ion was investigated by means of fluorescence spectra. The results showed that the pH value of the solution had obviousan influence on the fluorescence intensity of L 2·Tb 3+ complex, but the fluorescence intensity was hardly changed over the pH range from 6 to 11. The complex exhibits a higher emission quantum yield( φ =0.31) in aqueous solution, which indicates energy transfer type emission. The complexation behavior of L 2 with trivalent lanthanoid ions(Tb 3+ and Eu 3+ ) was also studied in aqueous boracic acid(hydrochloric acid buffer solution(pH 8.0) at 25 ℃ by UV Vis and fluorescence measurements. The spectrophotometric titrations have been performed to give the complex stability constants( K S) for the stoichiometric 1∶1 inclusion complexation of L 2 with Tb 3+ and Eu 3+ . The complex stability for L 2·Eu 3+ was higher than that for L 2·Tb 3+ , but no characteristic fluorescence was found.
文摘The synthesis of new chromogenic p (o,m,p carboxylazo)Calixarenes derivatives through the couping of diazotized o,m,p aminobenzene carboxylic acid and calixarenes was described.Their structures were comfirmed by IR, 1H NMR and elemental analysis.Their chromogenic properties and UV Vis absorption spectra were investigated under different pH conditions.Experimental results show that the synthesized derivatives can be used as new indicators and host
