Diverse CdII coordination complexes derived from bromide isophthalic acid binding with auxiliary N-donor ligands

The coordination characteristics of 4-bromoisophthalic acid (4-Br-H(2)ip) have been investigated in a series of Cd-II-based frameworks. Hydrothermal reactions of Cd-II salts and 4-Br-H(2)ip together with flexible or semiflexible N-donor auxiliary ligands resulted in the formation of four three-dimensional co-ordination complexes with diverse structures: {Cd(bix)(0.5)(bix)(0.5)(4-Br-ip)]center dot H2O}(n) (1), [Cd (bbi)(0.5)(bbi)(0.5)(4-Br-ip)](n) (2), {[Cd(btx)(0.5)(4-Br-ip)(H2O)]center dot 0.5CH(3)OH center dot H2O}(n) (3) and {[Cd(bbt)(0.5)(4-Br-ip) (H2O)]center dot 3 center dot 5H(2)O}(n) (4). These compounds were characterized by elemental analyses, IR spectra, single crystal and powder X-ray diffraction. They displayed diverse structures depending on the configuration of the 4-connected metal node, the coordination mode of the 4-Br-H(2)ip, the coordination ability and conformationally flexibility of the N-donor auxiliary. Compound 1 exhibits 3-fold interpenetrated 6(6) topology and compound 2 has a 4(12) topology. Compounds 3-4 have similar 3D pillar-layered structures based on 3,4-connected binodal net with the Schlafli symbol of (4-3(8)). The thermal stabilities and photoluminescence properties of them were discussed in detail. (C) 2016 Elsevier Inc. All rights reserved.