Mixed Thioether/Amine-Functionalized Expanded Calixarenes, Related Macropolycycles, and Metal Complexes thereof

A series of tetraaza-expanded calix[4]arene analogues (2-4), in which two of the four aryl groups are ethylene-protected thiophenol components were prepared from tetraaldehyde 1. Two of these strapped macrocycles were characterized crystallographically, as well as the dipalladium complex of 4. The same tetraaldehyde had been previously used for the synthesis of a macrotricycle (5) and a macropentacycle (6), the coordination properties of which have been investigated. In particular, ligand 6 was shown to be able to encapsulate a Cu+ or a Ag+ ion in the tetrahedral coordination pocket offered by a bridgehead nitrogen atom and the three proximal thioether sulfur atoms. N,S-expanded calix[4]arene analogues and a related macropentacycle are compartmental macrocycles incorporating -S(CH2)2S-bridges and nitrogen bridgehead atoms that make possible the formation of mixed aza-thioether complexes. Members of this family are the binuclear [Pd(N,S)Cl2] complex of a macrobicycle (illustration) and the mononuclear [M(N,4S)]+ (M=Cu+ and Ag+) complexes of a macropentacycle.image