Synthesis, structure, and ion-binding studies of cobalt(II) complexes with aza-crown substituted salicylaldimine Schiff base ligand

Abstract

A series of cobalt(II) complexes with azacrown ether-containing salicylaldimine Schiff base ligand Co(L1), Co(L2)2 and Co(L3)2 has been successfully synthesized. The cation-binding properties of the complexes have been studied and the stability constants with alkali and alkaline earth metal cations determined. Synthesis of the complexes with monoaza-12-crown-4, Co(L1) and Co(L2)2, allows for a direct comparison of the cation binding properties between the mono- and bis-Schiff base systems as well as with the complex containing the monoaza-15-crown-5 pendant, i.e. Co(L3)2, which has a different crown size. The X-ray crystal structure of Co(L3)2 has also been determined. © 2002 Elsevier Science B.V. All rights reserved.