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

Abstract

Five zinc coordination polymers {[Zn2(mtrb)2(btec)]·H2O}n (1), {[Zn(mtrb)(Meip)]·H2O}n (2), [Zn(mtrb)(nip)]n (3), {[Zn(mtrb)(hip)]·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 {62.84}{64.82}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 μM, 5.72 μM, and 6.28 μM, respectively. The luminescence sensor is stable and can be recycled for detection at least five times. The possible quenching mechanisms were discussed.