Self-assembled hybrid water-chloride-ethanol chain in Schiff base Co(III) complex: synthesis, structure, and properties

A new Co(III) complex, [CoL2] ⋅ (Cl)(EtOH)(H2O)2 (1) with tridentate 5-bromo-N-(8-quinolyl)salicylaldimine (HL) has been synthesized and structurally characterized. The Co(III) is coordinated by two tridentate Schiff-base ligands and the CoN4O2 core shows distorted octahedral coordination geometry. A hybrid water chain is formed by self-assembly of octameric water-chloride-ethanol clusters [(H2O)4(Cl)2(EtOH)2]2- consisting of cyclic chair-like hexamer and two dangling water molecules. These hybrid water clusters occupy voids in the crystals and display extensive H-bonding interactions with the host complexes, thus playing a key role in the formation of 3-D structure.