New Zn(II) and Cd(II) Coordination Polymers with 1,2-Benzenedicarboxylic Acid: Synthesis and Structures

Abstract

1,2-Benzenedicarboxylic (phthalic) acid (1,2-BdcН₂) and bipyridine ligands are used for the synthesis of the Zn(II) and Cd(II) coordination polymers. As a result, the target assembling of four complexes is carried out. The structures of the synthesized complexes are studied by X-ray diffraction analysis. Three of the obtained compounds are new coordination polymers [Zn₂(1,2-Bdc)₂(Bpe)₂]_n · 0.25n(Dmf) · 0.25nH₂O (I), [Zn₂(1,2-Bdc)₂(Bpp)₂]_n (II), and [Cd(1,2-Bdc)(Bpp)(H₂O)]_n (III) (Bpe is bis(4-pyridyl)ethane, Bpp is 1,2-bis(4-pyridyl)propane, and Dmf is dimethylformamide) (CIF files CCDC nos. 1824264 (I), 1824265 (II), and 1824266 (III)), and the fourth one is the known Cd(II) compound [Cd(1,2-Bdc)(H₂O)]_n. The study of the structures of compounds I–III reveals the dimensionalities of the polymers: 3D for the Zn(II) polymer and 2D for the Cd(II) polymer. Different shapes of the coordination polyhedra of Zn(II) are found in compounds I and II, and different coordination modes of the doubly deprotonated ligand (1,2-Bdc)^2– to the metals are observed in compounds I–III.