Syntheses and structures of four copper(II) complexes constructed from m-ferrocenylbenzoate and N-donor ligands

A series of four m-ferrocenylbenzoate [m-ferrocenylbenzoate = Na(m-OOCH4C6Fc), Fc = (η5-C5H5)Fe(η5-C5H4)] copper(II) complexes Cu2(μ2-OOCH4C6Fc)4(CH3OH)2 (1), Cu(η2-OOCH4C6Fc)2(2,2′-bpy) (2), Cu(η2-OOCH4C6Fc)2(1,10-phen) (3) and [Cu(η2-OOCH4C6Fc)2(4,4′-bpy)]n (4) (bpy = bipyridine, 1,10-phen = 1,10-phenanthroline) have been synthesized by reactions of Cu(CH3COO)2·H2O with Na(m-OOCH4C6Fc) and three types of N-donor ligands, respectively. X-ray diffraction analysis reveals that 1 shows a dimeric structure with a Cu⋯Cu distance of 2.5872(16) Å. 2 and 3 exhibit a mononuclear structure. The adjacent mononuclear molecules are packed into a one-dimensional (1D) chain through the π–π interactions between the bpy rings in 2 or phen rings in 3. 4 displays a 1D zigzag chain structure. In 1, the m-OOCH4C6Fc anion adopts the bidentate-bridging coordination mode, whereas it adopts the bidentate-chelating coordination mode in 2–4. Magnetic study indicates that an antiferromagnetic interaction between the CuII ions exists in 1.