Abstract

One pot sequential reactions of silica gel with tetrachlorosilane/triethylamine mixture and after with the conical upper rim tetraphosphorylated tetrahydroxy(thia)calixarenes yielded porous organo-inorganic sorbents modified by spatially ordered phosphonate, phosphinate or phosphine oxide groups capable of co-operative binding of metal cations. The grafting improves efficacy of europium(III) sorption by the silica gels. DFT calculations of the calixarene-Eu³⁺ complexes predict a calixarene flattened cone conformation with the coordination of Eu³⁺ cation to three of four P = O oxygen atoms and one of the aromatic systems. Adding three water molecules excludes completely cation–π interactions.

摘要

硅胶与四氯硅烷/三乙胺混合物的一锅顺序反应，然后与圆锥形上缘四磷酸化四羟基（硫杂）杯芳烃的一锅顺序反应产生了多孔有机无机吸附剂，该吸附剂由空间有序的膦酸酯、次膦酸酯或氧化膦基团改性，能够协同结合金属阳离子。接枝提高了硅胶对铕(III)的吸附效率。杯芳烃-Eu ^{3+复合物的DFT计算预测了杯芳烃扁平圆锥构象，其中Eu 3+}阳离子与四个P = O氧原子中的三个和芳香族系统之一配位。添加三个水分子完全排除了阳离子-π相互作用。