Role of macrocyclic effect in complex formation of palladium(II) with ligands anchored on a solid support

Resumo

The method for grafting dithiacrown ether and its linear analogue to the silica surface using preliminary prepared organosilicon derivative is developed. The importance of the acylation step in the process of grafting is underlined. The acylation is required to prevent sorption of platinum metals complex anions by the anion exchange mechanism, the probability of which increases due to protonation of the spacer in an acidic medium. The interaction of palladium(II) with anchored ligands in hydrochloric acid media was studied in details. The comparative study of two sorbents revealed that the macrocyclic effect plays a negligible role in binding of palladi um(II) ions. Therefore, linear ligands are preferred for the development of sorbents for molecular recognition of platinum metals ions.