Synergistic effect of ligating and ionic functions, prearranged on a calix[4]arene

Abstract

The covalent attachment of two CMPO-functions and two anionic Cosan groups to the narrow rim of tert-butylcalix[4]arene leads to a dramatic increase of the extraction efficiency for the cone isomer; Am(3+) is removed from 5 x 10(-8) M solution to more than 99% by a single extraction step with a 3 x 10(-6) M solution of the calixarene.

tert‐Butyl‐calix[4]arenes Substituted at the Narrow Rim with Cobalt Bis(dicarbollide)(1–) and CMPO Groups – New and Efficient Extractants for Lanthanides and Actinides

“…A synergistic effect of 11 and 12 is seen, however, at c = 10 -3 , where D(Eu) for their mixture is similar to that for 6c*. [21] Surprisingly, however, a synergistic effect was observed for the mixture of tetra-Cosan [20] calix [4]arene 13 and tetra-CMPO calix [4]arene 14 (which is a relatively strong extractant itself). [10] As shown in Table 4, the Eu extraction capabilities of both calixarenes alone are negligible at the low concentration of c = 5ϫ 10 -6 .…”

“…1,3-Dinitriles 3, easily available as syn isomers for n = 2 and 4-7 (for n = 3, see below), were treated with two equivalents of 10 [20][21][22][23] in toluene/DME at room temperature in the presence of NaH as base for the deprotonation. In the case of 3a the formation of the almost pure cone isomer was indicated by the NMR spectrum of the crude product, and 4a was isolated in 76 % yield.…”

“…In this paper we present a detailed report on the synthesis of calix [4]arenes simultaneously substituted at their narrow rims in alternating order with two hydrophobic cluster anions A (-) and two CMPO functions B (for a schematic presentation of their structures see Figure 1). Results from extraction [21] and complexation studies based on these compounds are also presented.…”

Calixarene complexes with soft metal ions

“…This field of science develops rapidly due to promising properties of such complexes in chemistry as well as in other research areas; [148][149][150][151][152][153][154] here their use as sensors for metal ions 26,27 and as catalysts 22 deserves a special attention. One should point out formation of calixarene complexes with lanthanides [155][156][157] and actinides [158][159][160] in view of the importance of radioactive waste disposal for the environmental protection.…”

17-Crown-5 ether condensed with 11-vertex nido-carborane

“…As a rule, these substituents are introduced by nu cleophilic opening of dioxane derivatives 3 of cobaltacar boranes. [4][5][6][7] In addition, alkylation of amino 8 and thio substituted 9-11 polyhedral anions is used sometimes. In this work, we propose an alternative approach to the syn thesis of carborane crown ethers based on the conden sation of easily accessible 1,2 bis(hydroxymethyl) ortho carborane.…”