Syntheses, structures and magnetic properties of five 5-bromoisophthalate coordination polymers with dipyridyl-type auxiliary ligands.

Five 5-bromoisophthalate coordination polymers were prepared and structurally characterized. Complexes 1 – 3 are 2D double-layered networks constructed from 1D [M 2 (5-Br-ip) 2 ] n (M = CoII/NiII/ZnII) double chains pillared by azpy and 4,4′-bipy spacers. Complexes 4 and 5 are 3D porous MOFs assembled by 2D wave-like [Zn(bpmba)] n networks connected by 5-Br-ip2− linkers. Complexes 1 and 2 show weak antiferromagnetic couplings in carboxylate-bridged Co 2 (CO 2) 2 and Ni 2 (CO 2) 2 dimers. • Five 5-bromoisophthalate coordination polymers were prepared. • These complexes exhibit 2D double-layered networks and 3D porous MOFs. • Complexes 1 and 2 show antiferromagnetic couplings in carboxylate-bridged CoII/NiII dimers. 5-Bromoisophthalic acid (5-Br-H 2 ip) reacts with metal nitrates and dipyridyl-type auxiliary ligands to afford five coordination polymers, [Co 2 (5-Br-ip) 2 (azpy) 2 ] n ∙2 n H 2 O (1), [Ni 2 (5-Br-ip) 2 (4,4′-bipy) 2 ] n ∙5 n H 2 O (2), [Zn(5-Br-ip)(4,4′-bipy)] n · n H 2 O (3), [Zn 2 (5-Br-ip)(bpmba) 2 (H 2 O) 2 ] n ∙ n DMF(4), [Zn 2 (5-Br-ip)(bpmba) 2 ] n ∙2 n H 2 O (5) (azpy = 4,4′-azobispyridine; 4,4′-bipy = 4,4′-bipyridine; Hbpmba = 3,5-bis(pyridin-4-yl-methoxy)benzoic acid). These complexes are characterized by elemental analysis, IR, PXRD, thermogravimetry and single crystal X-ray structural analysis. Complex 1 is a 2D double-layered network constructed from [Co 2 (5-Br-ip) 2 ] n double-chains pillared by azpy spacers. Complexes 2 and 3 are 2D double-layered networks using 4,4′-bipy as spacer. Complexes 4 and 5 are different 3D porous metal–organic frameworks (MOFs) assembled by 2D wave-like [Zn(bpmba)] n networks and bidentate 5-Br-ip2− linkers. Both complexes show (3,4)-connected jea-type nets of {63}{65·8} topology. The five complexes are thermally stable up to 350–410 °C. Complexes 1 and 2 show weak antiferromagnetic interactions in the carboxylate-bridged Co 2 (CO 2) 2 and Ni 2 (CO 2) 2 dimers. [ABSTRACT FROM AUTHOR]