Synthesis, Crystal Structure, and Properties of Two 2D Lamella Coordination Polymers Generated from Unsymmetrically Carboxylate Bridging Ligand

Self-assembly between simple unsymmetrical ligands, such as h₂epda (5-ethyl-pyridine-2,3-dcarboxylic acid) and H₂hmph(homophthalic acid) and two transition metals produce two new 2D lamella coordination polymers [Cu(hedpa)₂]_n1 and [Co(hmph)(bpe)]_n2 (bpe = 1,2-di(4-pyridyl)ethylene), respectively. The 2D lamella structure of 2 features hmph-bridged binuclear cobalt(II) chains joined by less flexible trans-bpe ligands, whereas the 2D layer of 1 manifests that unsymmetrical ligand h₂epda directly bridges mononuclear copper(II) running along the bc plane. The thermogravimetric (TG) reveal that both compounds are stable. Magnetic measurements show that complex 2 exhibits global metamagnetic behaviors.