A three-dimensional twofold interpenetrated cobalt(II) MOF containing a flexible carboxylate-based ligand: synthesis, structure and magnetic properties

Abstract

The design and synthesis of coordination polymers (CPs) have attracted much interest due to the intriguing diversity of their architectures and topologies. The functional solid catena-poly[μ2-aqua-triaqua{μ4-5-[4-carboxyphenoxy)methyl]benzene-1,3-dicarboxylato}{μ3-5-[4-carboxyphenoxy)methyl]benzene-1,3-dicarboxylato}dicobalt(II)], [Co2(C16H10O7)2(H2O)4] n or [Co2(HL)2(μ2-H2O)(H2O)3] n , was synthesized successfully by self-assembly of CoII ions with 5-[(4-carboxyphenoxy)methyl]isophthalic acid (H3 L). The title compound was obtained under hydrothermal conditions and exhibits a twofold interpenetrated three-dimensional skeleton with hms 3,5-conn topology according to the cluster representation for valence-bonded metal–organic frameworks (MOFs). It has been characterized by single-crystal X-ray diffraction, IR spectroscopy, powder X-ray diffraction (PXRD), thermogravimetric analysis and susceptibility measurements. The antiferromagnetic coupling between adjacent CoII centres occurs via superexchange through the ligands.