Self-assembly of ion-pair complexes

Abstract

Solid-state structures of cobalt(II) complexes of 4-methylumbelliferone-8- methyleneiminodiacetic acid (H 3muia), also named Calcein Blue, are presented. Interestingly, ion-pair complexes with different solvation in cation, namely, [Co(H 2O) 4(CH 3-CN) 2] [Co(muia)(H 2O) 2] 2 (1) and [Co(H 2O) 6][C o2(muia) 2(H 2O) 2]·2CH 3CN (2), exhibit self-assembly in one-pot crystallization. By variation of the experimental conditions, 1D coordination polymer [{Co(H 2O) 4}{Co 2(muia) 2(H 2O) 2}]·11H 2O (3), which can be considered a pseudo-supramolecular isomer, is obtained. Hydrogen bonding between the cation and anion core gives an interesting hydrogen-bonded network structure. The condensation of ion-pair complexes to a 1D coordination polymer by the influence of solvents is demonstrated. © 2007 American Chemical Society.