摘要
Calix[4]arene derivatives have been reported to possess high selectivity for metal ions.In order to analyze the extraction effect of substituents on Hg^(2+)and Pb^(2+),calix[4]arene derivatives containing hydroxyl,bromoethoxy and 1,11-dioxa-4,8-dithiahendecene were successfully synthesized,with their extraction effectiveness towards Hg^(2+)and Pb^(2+)were evaluated respectively.The results indicated that the phenolic hydroxyl in calix[4]arene improved the extraction ability on Hg^(2+)by promoting the formation of the negative oxygen ions that could bind with Hg^(2+)by coordination and ionic bonds.The extraction ability of 5,17-dinitro-26,28-(1’,11’-dioxa-4’,8’-dithiahendecene)-calix[4]arene(calix[4]arene thia derivative)was improved slightly due to the better coordination capacity for metal ions after introduction of 1,11-dioxa-4,8-dithiahendecene,which was a chelate-binding centre.Regarding to Pb^(2+),only 1,11-dioxa-4,8-dithiahendecene on molecule contributed to extraction due to the coordination bond.Since the metal ion with higher charge-to-radius ratio could coordinate with one ligand more stably,Pb^(2+)with higher charge-to-radius ratio than Hg^(2+)was coordinated and extracted by the calix[4]arene thia derivative more easily.Furthermore,extraction rates of the calix[4]arene thia derivative on both ions(Hg^(2+)and Pb^(2+))increased with the increase of pH value in acidic aqueous system(pH<7).
Calix[4]arene derivatives have been reported to possess high selectivity for metal ions. In order to analyze the extraction effect of substituents on Hg2＋ and Pb2 ＋ , calix [ 4 ] arene derivatives containing hydroxyl, bromoethoxy and 1, 11-dioxa-4, 8- dithiahendecene were successfully synthesized, with their extraction effectiveness towards Hg2 ＋ and Pb2 ＋ were evaluated respectively. The results indicated that the phenolic hydroxyl in calix [ 4 ]arene improved the extraction ability on Hg2＋ by promoting the formation of the negative oxygen ions that could bind with Hg2 ＋ by coordination and ionic bonds. The extraction ability of 5, 17- dinitro-26, 28-（ 1＇, 11＇-dioxa-4＇, 8＇-dithiahendecene）-calix[4] areae （calix[ 4] arene thia derivative） was improved slightly due to the better coordination capacity for metal ions after introduction of 1, 11-dioxa-4, 8-dithiahendeceae, which was a chelate-binding centre. Regarding to Pb2＋ , only 1, 11-dioxa-4, 8-dithiahendecene on molecule contributed to extraction due to the coordination bond. Since the metal ion with higher chargeoto-radius ratio could coordinate with one ligand more stably, Pb2 ＋ with higher charge-ta-cadins ratio than Hg2 ＋ was coordinated and extracted by the calix[ 4 ] arene thia derivative more easily. Furthermore, extraction rates of the calix[4]arene thia derivative on both ions （Hg2＋ and Pb2＋ ） increased with the increase of pH value in acidic aqueous system （ pH 〈7）.
基金
Natural Science Foundation of Education Department of Anhui Province,China(No.KJ2013B028)
Textile Science and Technology Key Discipline in Anhui Polytechnic University,China
