Syntheses, structures, properties of a series of coordination polymers with flexible bis(imidazole) and dicarboxylate ligands

Abstract

Seven coordination polymers, [Co(bix)(ndc)]n (1), [Co2(bix)(glu)2]n (2), {[Zn(bix)(male)]·H2O}n (3), [Zn2(bix)(pim)2]n (4), [Zn(bix)(aze)]n (5), {[Zn(bix)(mbda)]·H2O}n (6) and [Zn(bix)(adc)]n (7), were synthesized (bix=1,4-bis(2-methyl-imidazol-1-methyl)benzene, ndc=1,4-naphthalenedicarboxylate, glu=glutarate, male=maleicate, pim=pimelate, aze=azelaicate, mbda=1,3-benzenediacetate, adc=1,3-adamantanedicarboxylate). 1 shows an unusual 4-connected self-catenated 3D network. 2 is a 6-connected self-catenated 3D network based on the [Co2(COO)4] unit. 3 shows a special 2D (6,3) network, with six Zn(II) atoms at six corners and four bix and two double male ligands at six edges. 4 is a (3,4)-connected 3D network. 5 and 6 show the 2D (4,4) network. 7 consists of one-dimensional chains containing two alternative kinds of rings, [Zn2(adc)2] and [Zn2(bix)2]. The diverse structures indicate that the structures of the coordination polymers can be tuned by the right combination of appropriate flexible bis(imidazole) ligand, bix, the metal ions and dicarboxylate ligands. 1 and 2 are effective photocatalytic catalysts for the degradation of methyl orange. The luminescence of 3–7 and thermal stability of 1–7 were also investigated.