Synthesis, structure and luminescent properties of halogenated isophthalic acid-directed frameworks in virtue of flexible and semiflexible N-containing ligands

Abstract

Four three-dimensional (3D) coordination complexes on the basis of 4-halogenated isophthalic acid and two types of flexible and semiflexible N-donor ligands, formulated as {[Zn(bix)(4-Br-ip)]·H2O}n (1), {[Co(bix)(4-Br-ip)]·0.5H2O}n (2), [Zn(bbi)(4-Br-ip)]n (3) and [Co(bbi)(4-Cl-ip)]n (4), (4-Br-H2ip = 4-bromoisophthalic acid, 4-Cl-H2ip = 4-chloroisophthalic acid, bix = 1,4-bis(imidazol-1-yl-methyl)benzene, bbi = 1,1′-(1,4-butanediyl)bis(imidazole)), have been synthesized and characterized by elemental analyses, IR spectra, single-crystal and powder X-ray diffraction analyses. Compounds 1 and 2 possess the same 4-connected 66 net. Compounds 3 and 4 are isostructural and exhibit the 4-connected 412 topology. The thermal stabilities for 1–4 and photoluminescence properties for the d10 metal centers were discussed in detail.