New heterometallic coordination polymers constructed from 3d–3d′ binuclear nodes

Abstract

Heterobinuclear [Cu^IIMn^II] and [Cu^IICo^II] cationic complexes can efficiently act as nodes for designing coordination polymers. The crystal structures of two binuclear precursors, [LCuCo(NO₃)₂] (1) and [LCuMn(NO₃)₂] (2), have been solved (L²⁻ is the dianion of the Schiff base resulting from the 2 : 1 condensation of 3-methoxysalicyladehyde with 1,3-propanediamine). The nitrato ligands, coordinated to Co^II and, respectively, the Mn^II ions from the precursors, are easily replaced by exo-dentate ligands, resulting in 1-D coordination polymers: ¹_∞[L(H₂O)CuCo(oxy-bbz)]·CH₃CN·C₂H₅OH (3), ¹_∞[L(H₂O)CuCo(2,5-dhtp)]·CH₃CN (5) and _∞[L(H₂O)CuMn(ox)]·3H₂O (6) (oxy-bbz²⁻ = the dianion of 4,4′-oxy-bis(benzoic) acid; 2,5-dhtp²⁻ = the dianion of 2,5-dihydroxy-terephthalic acid; ox²⁻ = the dianion of the oxalic acid). In the case of the [CuMn] node, the interaction with oxy-bbz²⁻ affords a binuclear complex, [LCuMn(oxy-bbz)(H₂O)₂] (4).