Design and construction of coordination polymers by 2,2′-dinitro-4,4′-biphenyldicarboxylate and imidazole-based ligands: diverse structures based on different metal ions

Abstract

Six coordination polymers, [Mn₂(nbpdc)₂(bib)]_n (1), [Co₂(nbpdc)₂(bib)_1.5(H₂O)₂]_n (2), [Ni₂(nbpdc)₂(bib)_1.5(H₂O)₂]_n (3), [Cu₃(nbpdc)₂(bib)(OH)₂]_n (4), [Zn₂(nbpdc)₂(bib)]_n (5), and [Cd₂(nbpdc)₂(bib)(H₂O)]_n (6), (H₂nbpdc = 2,2′-dinitro-4,4′-biphenyldicarboxylic acid, bib = 1,4-bis(imidazol-1-yl)butane), have been prepared and structurally characterized. In these compounds, nbpdc and bib link different secondary building units (SBUs) to construct various architectures based on different metals. Compounds 1 and 5 present a 3D pcu net based on an infinite rod-shaped SBU. Compounds 2 and 3 have the same 2D double-layer structure with a unique {4¹².5².6} topology, showing an interesting self-penetration feature. Compound 4 presents a 3D framework with hex topology. Compound 6 shows a 3D framework with unprecedented (4¹².5¹³.6³)(4⁸.5⁵.6²) topology based on two different unusual infinite and finite SBUs, and has an interesting self-penetrating feature. Therefore, different metal ions influence the final structures of coordination polymers. Magnetic properties of compounds 1 and 4 have been characterized.