Two dinuclear copper(II) coordination polymers constructed from m-hydroxybenzoic acid and N-donor ligands: synthesis, crystal structures, and magnetic properties

Abstract

Two dinuclear Cu(II) complexes, [Cu2(4,4′-bpy)(m-bza)4]·3H2O·2DMF 1 and [Cu2(2,2′-bpy)2(m-bza)3](NO3) 2 (m-Hbza = m-hydroxybenzoic acid), were synthesized and characterized by X-ray diffraction methods, physicochemical and spectroscopic methods plus magnetic measurements. In complex 1, the paddle wheel binuclear Cu(II) cores are bridged by 4,4′-bpy ligands to form 1D chains which are further assembled into a 3D network through hydrogen bonding, with a topology of (44 × 610 × 8)(44 × 62). The dinuclear Cu(II) clusters in complex 2 are paired to generate hydrogen-bonded tetranuclear motifs, which are assembled via hydrogen bonds into 2D supramolecular layers and further assembled into a 3D supramolecular network through π⋯π stacking interactions with topology of (4 × 6 × 83 × 10)(4 × 62 × 83)(62 × 8). Variable-temperature magnetic susceptibility measurements show that both complexes exhibit antiferromagnetic coupling exchange.