A macrobicyclic AgI3 cage encapsulating two cobalt(III) ions:: synthesis, structure and reactivity

Reaction of the S-bridged (Co2Ag3I)-Ag-III pentanuclear complex, [Ag-3(I){Co-III(aet)(3)}(2)](3+) (1; aet = NH2CH2CH2S-), with paraformaldehyde in basic acetonitrile, followed by adding aqueous ammonia, produces the aza-capped complex, [Ag-3(I)-{Co-III(L)}(2)](3+) [2; L = N(CH2NHCH2CH2S-)(3)], in which two Co-III atoms are encapsulated in a macrobicyclic cage consisting of two aza-capped ligands L and three Ag-I atoms; 2 is converted to the aza-capped (Co4Zn4II)-Zn-III octanuclear complex, [(Zn4O)-O-II{Co-III(L)}(4)](6+), by the reaction with I- in the presence of ZnO and Zn2+ in water, retaining the chiral configuration of the aza-capped [Co-III(L)] units.