SYNTHESIS OF DICOPPER [3]-CATENATES AND [3]-CATENANDS BY ACETYLENIC OXIDATIVE COUPLING - PREPARATION AND STUDY OF CORRESPONDING HOMODIMETALLIC [3]-CATENATES (AG+, ZN-2+, CO-2+, AND NI-2+)

[3]-Catenates have been prepared in good yield by double acetylenic oxidative coupling from a terminal diyne threaded into a preformed ring. The central macrocyle is a 44-membered ring, whereas the peripheral subunits consist of 27- or 30-membered rings; the dicopper [3]-catenates are obtained in 68% or 58% yield, respectively. Besides these molecular systems containing three interlocked rings, a significant proportion of [4]-catenates was also isolated, the overall yield of interlocking cyclic products thus amounting to 80%. The corresponding [3]-catenands could be prepared by removal of the templating copper(I) centers by KCN. Remetalation of a [3]-catenand by various transition metals (Ag+, Zn2+, Co2+, or Ni2+) led to new symetrical dimetallic species. These complexes were fully characterized. A detailed electrochemical study showed some electrostatic interaction between the cationic complex subunits within the same molecule, provided the system was folded up so as to bring the two subcomplexes to a relative proximity. Some indication about the geometry of the molecule in solution could thus be obtained by electrochemical measurements. © 1990, American Chemical Society. All rights reserved.