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A novel 3D Zn-based coordination polymer (NH 2 -LCU-110 , LCU names Liaocheng University) with the formula [Zn(L1)(bpea) n (H 2 L1 ​= ​2-aminoterephthalic acid, bpea ​= ​1,2-bis(4-pyridyl)ethane), was hydrothermally synthesized from a flexible nitrogen-containing carboxylic acid ligand with various coordination modes as main ligands and nitrogen-containing auxiliary ligand with different structures. NH 2 -LCU-110 demonstrates an interesting 5-fold interpenetrating diamond structure. Luminescence measurements reveal that this complex has obvious emission enhancement and quenching towards Al3+ and Cu2+, respectively. The mixed matrix membranes (MMMs) incorporating NH 2 -LCU-110 and poly(methyl methacrylate) (PMMA) as well as simple test papers were both prepared for potential application. The MMMs can quickly detect Al3+ and Cu2+ and the original emission could be regenerated by lifting from the analytical solutions, demonstrating its fast response and good selectivity. The sensing mechanism was investigated in details by various measurements and compared with isostructural complex LCU-110 without –NH 2 groups. All observations indicate that introduction of Lewis basic –NH 2 groups can enhance the intermolecular interactions between the frameworks of coordination polymers and sensing analytes (Al3+ and Cu2+). An amino-functionalized coordination polymer NH 2 -LCU-110 exhibits luminescence turn-on/off toward Al3+/Cu2+, and its mixed matrix membranes and test papers were prepared. [Display omitted] • An amino-functionalized coordination polymer was employed as a multiresponsive luminescence sensor. • NH 2 -LCU-110 exhibits luminescence turn-on and turn-off behavior toward Al3+ and Cu2+, respectively. • Mixed matrix membranes (MMMs) and test papers made the detection more simple and convenient. [ABSTRACT FROM AUTHOR]

The three multi-dimensional coordination polymers, [Mn 2 (μ 4 -dttpa)(μ 6 -dttpa)(H 2 O) 2 ] n (1), {[Co(μ 4 -dttpa)(H 2 O) 2 ]·2H 2 O} n (2), and {[Zn 3 (μ 4 -dttpa) 2 (μ 2 -dttpa)(phen) 2 (H 2 O) 2 ]·2H 2 O} n (3) (H 2 dttpa ​= ​2,5-di(1H-1,2,4-triazol-1-yl)terephthalic acid; phen ​= ​1,10- phenanthroline), are successfully synthesized and characterized by X-ray single crystal diffraction, powder X-ray diffraction (PXRD), FT-IR spectra, elemental analysis and thermogravimetric analysis. Structurally, complex 1 is a three-dimensional structure with the 3-nodal Schläfli point symbol of {4·63·82} 2 {42·62·82}{62·84}. Complex 2 displays a two-dimensional network with a 6-connected uninodal net. With the point symbol of {4·62} 2 ·{43·63} 2 ·{44·62}{6}, complex 3 shows the two-dimensional stacking pattern. Temperature-dependent magnetic data of complexes 1 and 2 indicate antiferromagnetic behaviors between adjacent metal ions from 2 ​K to 300 ​K. Further magnetic studies show that the best fitting parameters of comple× 1 are obtained using the dinuclear Mn(II) model. From 50K to 300K, complex 2 displays antiferromagnetism over its mononuclear analogue with the zero-field splitting parameter (|D| ​= ​35.2 ​cm−1). The luminescent intensity of complex 3 is much stronger than that of free ligand (H 2 dttpa) and auxiliary ligand (phen). Moreover, the photoluminescence mechanism of complex 3 has been analyzed by theoretical calculation at ωB97XD/6–311++g(2d,p) level with DFT and TDDFT, which reveals that luminescence emission of 3 is attributed to the ligand-to-ligand charge transfer (π∗ phen -π dttpa2-). Compared with the free ligand, the enhancement of the luminescent intensity of compound 3 might occur due to the construction of Zn(II) ion, dttpa2− and phen increases the efficiency of charge transfer between LUMO and HOMO in the solid state. [Display omitted] • The luminescence mechanism of Zinc(II) compound has been elaborated by DFT and TDDFT analysis. • Summary and comparison of dttpa2− complexes in this paper and published in literature. • A new coordination mode μ 2 -(η1)-(η1) of dttpa2− in the solid state is first published. [ABSTRACT FROM AUTHOR]