Copper(ii) and nickel(ii) coordination polymers assembled from 2,4-dibenzoylisophthalic acid and different N-donor co-ligands: syntheses, crystal structures, and magnetic properties

Abstract

Four new coordination polymers based on 2,4-dibenzoylisophthalic acid and different N-donor auxiliary co-ligands, {Cu₂L₂(4,4′-bpy)}_n (1), {Ni₂L₂(4,4′-bpy)}_n (2), {[Cu₁₀(L)₈(bbi)(μ₃–OH)₄(H₂O)₆]·4H₂O}_n (3) and {[CuL(bth)(H₂O)]·H₂O}_n (4) (H₂L = 2,4-dibenzoylisophthalic acid, 4,4′-bpy = 4,4′-bipyridine, bbi = 1,1′-(1,4-butanediyl)bis(imidazole) and bth = 1,6-bis(1,2,4-triazol-1-yl)hexane), have been synthesized under hydrothermal conditions and characterized by single crystal X-ray diffraction, elemental analysis, IR spectroscopy, UV-Vis spectra, powder X-ray diffraction and thermogravimetric analysis. Complexes 1 and 2 are isostructural and crystallized in the chiral space groupP3₂21. They both possess three-dimensional (3D) coordination frameworks with 6-connected (4⁴·5¹⁰·7) topology that are incorporated left-handed helices and right-handed double helices substructures based on M(II) (M = Cu, Ni) paddle-wheel clusters. Complex 3 exhibits a 3D (4,5)-connected network with (4⁴·6²) (4⁴·6⁶) topology, in which dinuclear Cu₂(CO₂)₄ clusters act as 4-connected nodes and tetranuclear [Cu₄(μ₃–OH)₂]⁶⁺clusters serve as 5-connected nodes. Complex 4 shows a two-dimensional (2D) parallelogrammic network with (4,4) topology. The magnetic properties for 1–3 have been investigated and exhibited antiferromagnetic interaction.