Two new substituted calix[4]arene derivatives 2 and 3 were synthesized by the reaction of calix[4]arene with methyl o-bromomethyl-benzoate in the presence of potassium carbonate under nitrogen. Their compositions and ...Two new substituted calix[4]arene derivatives 2 and 3 were synthesized by the reaction of calix[4]arene with methyl o-bromomethyl-benzoate in the presence of potassium carbonate under nitrogen. Their compositions and structures were confirmed by elemental analysis, IR, 1H NMR and 13C NMR. Both the compounds are in the cone conformation. The percent extraction of the tetrasubstituted calix[4]arene derivative 2 for Li +, Na +, K + and Cs + are 6.8, 19.4, 69.8 and 7.1, respectively, indicating that derivative 2 extracts K + better than Li +, Na + and Cs +. The higher selective complexation of compound 2 with K + elucidated that the radius of potassium cation may be matched with the inclusion cavity formed by the carbonyl and phenoxy groups. There is only a little extractivity of disubstituted calix[4]arene derivative 3 for alkali metal ions.展开更多
A modified [3+1] cyclization procedure for the synthesis of calix [4]arenes was developed by using diglycol dimethyl ether as the solvent in place of dioxane which was generally adopted in previous literature. By the ...A modified [3+1] cyclization procedure for the synthesis of calix [4]arenes was developed by using diglycol dimethyl ether as the solvent in place of dioxane which was generally adopted in previous literature. By the modified procedure, the yield of 5-bromo-11, 23-di-tert-butyl-17-methyl-25, 26, 27, 28-tetrahydroxycalix[4]arene from cyclic condensation of 2, 6-bis(2’-hydroxy-5’-tert-butyl-benzyl)-4-cresol and 2, 6-bis (bromomethyl)-4-bromophenol in the presence of TiCl4 was improved from less than 20％ to 40％, and the reaction time was reduced from several days to ten hours.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
文摘Two new substituted calix[4]arene derivatives 2 and 3 were synthesized by the reaction of calix[4]arene with methyl o-bromomethyl-benzoate in the presence of potassium carbonate under nitrogen. Their compositions and structures were confirmed by elemental analysis, IR, 1H NMR and 13C NMR. Both the compounds are in the cone conformation. The percent extraction of the tetrasubstituted calix[4]arene derivative 2 for Li +, Na +, K + and Cs + are 6.8, 19.4, 69.8 and 7.1, respectively, indicating that derivative 2 extracts K + better than Li +, Na + and Cs +. The higher selective complexation of compound 2 with K + elucidated that the radius of potassium cation may be matched with the inclusion cavity formed by the carbonyl and phenoxy groups. There is only a little extractivity of disubstituted calix[4]arene derivative 3 for alkali metal ions.
文摘A modified [3+1] cyclization procedure for the synthesis of calix [4]arenes was developed by using diglycol dimethyl ether as the solvent in place of dioxane which was generally adopted in previous literature. By the modified procedure, the yield of 5-bromo-11, 23-di-tert-butyl-17-methyl-25, 26, 27, 28-tetrahydroxycalix[4]arene from cyclic condensation of 2, 6-bis(2’-hydroxy-5’-tert-butyl-benzyl)-4-cresol and 2, 6-bis (bromomethyl)-4-bromophenol in the presence of TiCl4 was improved from less than 20％ to 40％, and the reaction time was reduced from several days to ten hours.
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%.
