STABLE CU-BRIDGED MACROCYCLIC MOLECULES - STRUCTURE AND CHEMICAL-PROPERTIES(, AG+ COMPLEXES OF AZA)

The cage type compounds 1 and 2 form stable Cu+ or Ag+ complexes, whic h have been employed for the preparation of cation-free host molecules . A reaction between the potassium complex K(+)subset of 1 and a Cu-II salt generates a Cu-I complex, The Cu-II/Cu-I redox potential is obse rved at +0.43 V (vs. SCE) in the cyclic voltammetry, which shows that the Cu+ state is stabilized by its rigid molecular skeleton and spatia lly fixed coordination sites, A reaction between Ag+ and K(+)subset of 2 yields the dinuclear complex 2Ag(+)subset of 2, which has a short A g+...Ag+ distance (2.78 Angstrom). The halide anions (Cl-, Br-, I-) re move one Ag+ from 2Ag(+)subset of 2 to give Ag(+)subset of 2, but furt her demetallation does not occur, CV measurements show that these silv er complexes are electrochemically stable, Both silver complexes are s table to sunlight, The first preparations of guest-free hosts have bee n achieved by treating Cu(+)subset of 1 or 2Ag(+)subset of 2 with CN-. Inclusions of neutral guests (NH3, BH3) have been attempted using the se guest-free hosts.