Caesium Iodide Complex of 1,3-Calix[4]-bis-crown-6

Crown ether conformations in 1,3-calix[4]arene bis(crown ethers): crystal structures of a caesium complex and solvent adducts and molecular dynamics simulations *

“…4 In order better to understand the origins of this high selectivity, we are engaged in an investigation of the structural features of these compounds and their alkali-metal ion complexes, by single-crystal X-ray diffraction. [5][6][7][8][9] Some molecular dynamics simulations have also been performed with the aim of predicting the behaviour of new ligands. 6,9, 10 In these simulations the structural complementarity between the cation and the ligand appears to be a primary criterion.…”

“…[10][11][12] We have limited our structural investigations up to now to two ligands of this family: 1,3-calix [4]arene bis(18-crown-6) (1, see Scheme 1) and 1,3-calix [4]arene bis-(benzo-18-crown-6) 2 which have been shown, from solution experiments, to present a high caesium over sodium selectivity. We have reported previously the crystal structures of acetonitrile adducts of 1, 6,8 of its mono-and/or bi-nuclear caesium complexes with nitrate, 6 thiocyanate 5 or iodide 7 as counter ions and of its sodium and potassium complexes with nitrate counter ions. 9 We have also determined the crystal structures of the acetonitrile adduct of 2, 8 and of its binuclear caesium complex with nitrate counter ions.…”

Thiacalix[4]‐bis‐crown with Hard Cavities and Soft Bridges Exhibiting Endocyclic Potassium(I) Complexes and Exocyclic Silver(I) Coordination Polymers

“…Thiacalixarenes have attracted considerable interest as a partner of “classical” calixarenes due to their isostructural topology and the additional coordinating sites in form of sulfur bridges . One of the most fascinating modification of a (thia)calixarene scaffold involves linking of two opposite aromatic units with crown moieties to give (thia)calixcrowns . Calix[4]‐bis‐crown family and their thiacalix analogues exhibit interesting common features including (1) two crown cavities able to undergo dinucleation and (2) HSAB (hard and soft acids and bases) based complexation selectivity.…”

“…Calix[4]‐bis‐crown family and their thiacalix analogues exhibit interesting common features including (1) two crown cavities able to undergo dinucleation and (2) HSAB (hard and soft acids and bases) based complexation selectivity. In addition, some metal ions are entrapped and stabilized not only by cation–donor binding in the crown cavities but also by cation–π interaction , . As far as we know, six examples of group 1A metal ion complexes of (thia)calix[4]‐bis‐crowns incorporating crown‐5 and/or crown‐6 moieties have been isolated and structurally characterized …”

“…As mentioned, the homobinuclear complexation of the calix[4]‐bis‐(thia)crowns is well established for group 1A and Ag + ions . Only two examples of heterobinuclear complexes are reported.…”