Supramolecular assemblages from uranyl complexes of calixarenes and potassium complexes of 18-crown-6 or dibenzo-18-crown-6

Reaction of uranyl nitrate with p-tert-butyl[3.1.3.1]homocalixarene (L1H4) or p-tert-butylcalix[8]arene (L2H8) has been carried out in the presence of KOH and 18-crown-6 (18C6) or dibenzo-18-crown-6 (db18C6), giving the supramolecular assemblages [K(db18C6)(H2O)2]3 [{UO2(L1)}2K(H2O)5] (1) and [K(18C6)(OH)2][{(UO2)2(L2H5)(OH)}{K(18C6)}] (2). Compound 1 comprises a sandwich, “complex-within-complex” assemblage in which two uranyl/calixarene complexes encompass a potassium/crown ether guest. A direct bond between uranyl and K(18C6) is present in 2, in which a columnar arrangement of alternate dimetallic calixarene complexes and potassium/crown ether species is formed.

Two assemblages comprising uranyl/calixarene and potassium/crown ether complexes are described. A sandwich architecture is obtained with the smaller, cone-shaped p-tert-butyl[3.1.3.1]homocalixarene, whereas a columnar stacking is obtained with the larger and flatter p-tert-butylcalix[8]arene.Figure optionsDownload as PowerPoint slide