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Coordination polymer (CP) materials have an important application as sensors. In this work, two new Ni(II)/Zn(II)-CPs of sebacic acid (H2seb) and 1,6-bis(benzimidazole)hexane (bbimh), {[Ni3(seb)3(bbimh)4]·7H2O}n (1) and {[Zn(seb)(bbimh)]·H2O}n (2), were constructed as luminescent sensors. Ni(II)-CP 1 features a three-dimensional (3D) (4,5)-connected framework including 1D channels occupied by water molecules. Zn(II)-CP 2 shows a 3D supramolecular network with 6-connected pcu topology. Both CPs have good stability in aqueous solution as well as in EtOH. Luminescence sensing studies reveal that 1 and 2 display high luminescence quenching efficiency toward IO4−, 2,6-dichloro-4-nitrophenol (2,6-DCNP) and folic acid (FA). Both CPs also display excellent sensitivity with limits of detection toward IO4−, 2,6-DCNP and FA as low as 1.23 μM, 13.26 nM and 13.04 μM for 1 and 1.26 μM, 30.61 nM and 15.70 μM for 2, respectively. Additionally, the two CPs were also demonstrated to be ultrasensitive and selective sensors for the detection of IO4− in swimming pool water, 2,6-DCNP in farmland sewage and FA in human serum. The experimental results suggest that the synthesized Ni(II)/Zn(II)-CPs have potential application as luminescence sensing materials in environmental pollution and human health. [ABSTRACT FROM AUTHOR]

Two Cd(II) MOFs based on the 1,4-bis[(2-methyl-1H-imidazol-1-yl)-methyl]benzene (1,4-mbix) and succinate (Suc2−) or azelate (Aze2−) ligands have been hydrothermally synthesized, namely, {[Cd2(Suc)2(1,4-mbix)2]·5H2O}n (1) and [Cd(Aze)(1,4-mbix)]n (2). Both MOFs were structurally characterized by single-crystal X-ray diffraction. In MOF 1, the Cd(II) centers are connected by Suc2− and 1,4-mbix to generate a two-dimensional (2D) sql layer with (H2O)5 water cluster. Each 2D layer is further interlocked with two adjacent layers to form a 2D + 2D → 3D parallel polycatenated structure. In MOF 2, when the Suc2− was placed by Aze2−, the Cd(II) centers are connected by Aze2− and 1,4-mbix into a 2D sql layer but without any water molecules. And two 2D sql layers interpenetrate with each other to generate a twofold 2D + 2D → 2D sheet. MOFs 1 and 2 display photoluminescence at 343 nm (λex = 288 nm) and 298 nm (λex = 271 nm), respectively. Luminescent quenching experiments show that 1 and 2 have good ability for detection of Fe3+ in deionized water with low detection limits as 0.58 μM for 1 and 0.54 μM for 2, respectively. Two MOFs also can serve as luminescent sensors for Fe3+ in real tap water and river water. The luminescent quenching of 1 and 2 toward Fe3+ can be attributed to the competition among the absorption of Fe3+ with the excitation and emission of two MOFs. [ABSTRACT FROM AUTHOR]

Two Cd(II) MOFs based on the 1,4-bis[(2-methyl-1H-imidazol-1-yl)-methyl]benzene (1,4-mbix) and succinate (Suc2−) or azelate (Aze2−) ligands have been hydrothermally synthesized, namely, {[Cd2(Suc)2(1,4-mbix)2]·5H2O}n (1) and [Cd(Aze)(1,4-mbix)]n (2). Both MOFs were structurally characterized by single-crystal X-ray diffraction. In MOF 1, the Cd(II) centers are connected by Suc2− and 1,4-mbix to generate a two-dimensional (2D) sql layer with (H2O)5 water cluster. Each 2D layer is further interlocked with two adjacent layers to form a 2D + 2D → 3D parallel polycatenated structure. In MOF 2, when the Suc2− was placed by Aze2−, the Cd(II) centers are connected by Aze2− and 1,4-mbix into a 2D sql layer but without any water molecules. And two 2D sql layers interpenetrate with each other to generate a twofold 2D + 2D → 2D sheet. MOFs 1 and 2 display photoluminescence at 343 nm (λex = 288 nm) and 298 nm (λex = 271 nm), respectively. Luminescent quenching experiments show that 1 and 2 have good ability for detection of Fe3+ in deionized water with low detection limits as 0.58 μM for 1 and 0.54 μM for 2, respectively. Two MOFs also can serve as luminescent sensors for Fe3+ in real tap water and river water. The luminescent quenching of 1 and 2 toward Fe3+ can be attributed to the competition among the absorption of Fe3+ with the excitation and emission of two MOFs. [ABSTRACT FROM AUTHOR]

Two new CdII MOFs, namely, two‐dimensional (2D) poly[[[μ2‐1,4‐bis(1H‐benzimidazol‐1‐yl)butane](μ2‐heptanedioato)cadmium(II)] tetrahydrate], {[Cd(C7H10O4)(C18H18N4)]·4H2O}n or {[Cd(Pim)(bbimb)]·4H2O}n (1), and 2D poly[diaqua[μ2‐1,4‐bis(1H‐benzimidazol‐1‐yl)butane](μ4‐decanedioato)(μ2‐decanedioato)dicadmium(II)], [Cd2(C10H16O4)2(C18H18N4)(H2O)2]n or [Cd(Seb)(bbimb)0.5(H2O)]n (2), have been synthesized hydrothermally based on the 1,4‐bis(1H‐benzimidazol‐1‐yl)butane (bbimb) and pimelate (Pim2−, heptanedioate) or sebacate (Seb2−, decanedioate) ligands. Both MOFs were structurally characterized by single‐crystal X‐ray diffraction. In 1, the CdII centres are connected by bbimb and Pim2− ligands to generate a 2D sql layer structure with an octameric (H2O)8 water cluster. The 2D layers are further connected by O—H...O hydrogen bonds, resulting in a three‐dimensional (3D) supramolecular structure. In 2, the CdII centres are coordinated by Seb2− ligands to form binuclear Cd2 units which are linked by bbimb and Seb2− ligands into a 2D hxl layer. The 2D layers are further connected by O—H...O hydrogen bonds, leading to an 8‐connected 3D hex supramolecular network. IR and UV–Vis spectroscopy, thermogravimetric analysis and solid‐state photoluminescence analysis were carried out on both MOFs. Luminescence sensing experiments reveal that both MOFs have good selective sensing towards Fe3+ in aqueous solution. [ABSTRACT FROM AUTHOR]

Two new CdII MOFs, namely, two‐dimensional (2D) poly[[[μ2‐1,4‐bis(1H‐benzimidazol‐1‐yl)butane](μ2‐heptanedioato)cadmium(II)] tetrahydrate], {[Cd(C7H10O4)(C18H18N4)]·4H2O}n or {[Cd(Pim)(bbimb)]·4H2O}n (1), and 2D poly[diaqua[μ2‐1,4‐bis(1H‐benzimidazol‐1‐yl)butane](μ4‐decanedioato)(μ2‐decanedioato)dicadmium(II)], [Cd2(C10H16O4)2(C18H18N4)(H2O)2]n or [Cd(Seb)(bbimb)0.5(H2O)]n (2), have been synthesized hydrothermally based on the 1,4‐bis(1H‐benzimidazol‐1‐yl)butane (bbimb) and pimelate (Pim2−, heptanedioate) or sebacate (Seb2−, decanedioate) ligands. Both MOFs were structurally characterized by single‐crystal X‐ray diffraction. In 1, the CdII centres are connected by bbimb and Pim2− ligands to generate a 2D sql layer structure with an octameric (H2O)8 water cluster. The 2D layers are further connected by O—H...O hydrogen bonds, resulting in a three‐dimensional (3D) supramolecular structure. In 2, the CdII centres are coordinated by Seb2− ligands to form binuclear Cd2 units which are linked by bbimb and Seb2− ligands into a 2D hxl layer. The 2D layers are further connected by O—H...O hydrogen bonds, leading to an 8‐connected 3D hex supramolecular network. IR and UV–Vis spectroscopy, thermogravimetric analysis and solid‐state photoluminescence analysis were carried out on both MOFs. Luminescence sensing experiments reveal that both MOFs have good selective sensing towards Fe3+ in aqueous solution. [ABSTRACT FROM AUTHOR]

Two new Cd II MOFs, namely, two-dimensional (2D) poly[[[μ 2 -1,4-bis(1H-benzimidazol-1-yl)butane](μ 2 -heptanedioato)cadmium(II)] tetrahydrate], {[Cd(C 7 H 10 O 4 )(C 18 H 18 N 4 )]·4H 2 O} n or {[Cd(Pim)(bbimb)]·4H 2 O} n (1), and 2D poly[diaqua[μ 2 -1,4-bis(1H-benzimidazol-1-yl)butane](μ 4 -decanedioato)(μ 2 -decanedioato)dicadmium(II)], [Cd 2 (C 10 H 16 O 4 ) 2 (C 18 H 18 N 4 )(H 2 O) 2 ] n or [Cd(Seb)(bbimb) 0.5 (H 2 O)] n (2), have been synthesized hydrothermally based on the 1,4-bis(1H-benzimidazol-1-yl)butane (bbimb) and pimelate (Pim 2- , heptanedioate) or sebacate (Seb 2- , decanedioate) ligands. Both MOFs were structurally characterized by single-crystal X-ray diffraction. In 1, the Cd II centres are connected by bbimb and Pim 2- ligands to generate a 2D sql layer structure with an octameric (H 2 O) 8 water cluster. The 2D layers are further connected by O-H...O hydrogen bonds, resulting in a three-dimensional (3D) supramolecular structure. In 2, the Cd II centres are coordinated by Seb 2- ligands to form binuclear Cd 2 units which are linked by bbimb and Seb 2- ligands into a 2D hxl layer. The 2D layers are further connected by O-H...O hydrogen bonds, leading to an 8-connected 3D hex supramolecular network. IR and UV-Vis spectroscopy, thermogravimetric analysis and solid-state photoluminescence analysis were carried out on both MOFs. Luminescence sensing experiments reveal that both MOFs have good selective sensing towards Fe 3+ in aqueous solution.