The photochemistry of aqueous solutions of [Co(CN)5H2O]2- in the presence of the polyammonium macrocyclic receptor ane-N8H88+ was studied. The quantum yield for cyanide release in free [Co(CN)5H2O]2- (Φ=0.003 at 313 nm, pH 1.5) is reduced approximately threefold in the presence of the protonated macrocycle, which provides evidence for the formation of a supramolecular structure. Further evidence for the supramolecular structure is obtained from the thermal anation of [Co(CN)5H2O]-2 with Br- (40 °C, pH 1.0), the rate of which is increased in the presence of ane-N8H88+, suggesting that the ligand water is not involved in hydrogen bonds with the macrocycle. These results are interpreted in terms of possible supramolecular structures.
|Number of pages||7|
|Journal||Journal of Photochemistry and Photobiology A: Chemistry|
|Publication status||Published - 30 Jun 1992|