Construction of five zinc coordination polymers with 4-substituted bis (trizole) and multicarboxylate ligands: Syntheses, structures and properties

Five zinc coordination polymers {[Zn-2(mtrb)(2)(btec)]center dot H2O}(n) (1), {[Zn(mtrb)(Meip)]center dot H2O}(n) (2), [Zn(mtrb) (nip)(n), (3), {[Zn(mtrb)(hip)]center dot H2O}(n) (4) and [Zn(mtrb)(nbdc)(n) (5) (mtrb = 1,3-bis(1,2,4-triazol-4-ylmethyl)benzene, btec = 1,2,4,5-benzenetetracarboxylate, Meip = 5-methylisophthalate, nip = 5-nitroisophthalate, hip = 5-hydroxyisophthalate, nbdc = 4-nitro-1,2-benzenedicarboxylate) were synthesized and characterized. 1 shows a (4,4)-connected self-catenated 3D network with a point symbol of (6(2).8(4)){6(4).8(2)}(2), which belongs to the 4,4T32 topological type. 2 is a 1D chain structure containing [Zn (mtrb)(Meip)] 20-membered cycle. 3 is a 1D chain structure containing [Zn(nip)(2)] 16-membered cycle and [Zn(mtrb)(2)] 24-membered cycle. 4 and 5 exhibit the undulated 2D (4,4) network. 1 is a highly sensitive and selective luminescence sensor for detection of Cr2O72-, CrO42- and Fe3+ in the aqueous solution. The detection limits for Cr2O72-, CrO42- and Fe3+ are 3.05 mu M, 5.72 mu M, and 6.28 mu M, respectively. The luminescence sensor is stable and can be recycled for detection at least five times. The possible quenching mechanisms were discussed. (C) 2018 Elsevier Ltd. All rights reserved.