•A new (3,4,5)-connected 2D MOF based on the tetranuclear Cu4 units has been obtained.•Magnetic studies reveal magnetic interactions associated with the hydroxo bridges arising from different Cu-OH-Cu angles.•No magnetic ordering is observed for 1.Based on an asymmetric imidazole-1-acetic acid (Hima), a new polynuclear complex [Cu2(ima−)(SO42 −)(H2O)(OH−)]n 1 has been synthesized and characterized structurally and magnetically. Polymer a two-dimensional (2D) structure based on the tetranuclear Cu4 units, which displays a (3,4,5)-connected topology. The magnetic susceptibility data is dominated by magnetic interactions associated with the hydroxo bridges arising from different Cu-OH-Cu angles, which is in agreement with magneto-structural correlations found in the literature relative to such bridges in Cu(II) complexes.Complex 1 shows (3,4,5)-connected 2D structure based on the tetranuclear Cu4 units. Magnetic studies reveal magnetic interactions associated with the hydroxo bridges arising from different Cu-OH-Cu angles.Download high-res image (206KB)Download full-size image

•Five polymers have been synthesized and characterized.•Polymer 1 possesses a 2-fold interpenetrating three-dimensional framework.•The fluorescence properties of 1–5 are studied.•Magnetic properties of 5 are also investigated.Five new polymers based on 5-(pyridine-3-yl)pyrazole-3-carboxylic acid (H2ppca), namely, [Cd2(ppca)(bix)(SO4)]n (1), {[Cd(Hppca)2]·H2O}n (2), {[Mn(Hppca)2]·H2O}n (3), [Zn2(ppca)2]n (4) and [Cu(ppca)]n (5) have been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction, elemental analyses and IR spectroscopy. Structural analyses reveal that polymer 1 possesses a 2-fold interpenetrating three-dimensional (3D) framework. Polymers 2 and 3 display 4-connected 2D frameworks, while polymer 4 features a (3,3)-connected topology with the Schläfli symbol (4·8·10). 5 exhibits a 2D structure with the Schläfli symbol (4·82). Furthermore, the fluorescence properties of the five polymers are also investigated in the solid state, showing the fluorescence signal changes in comparing with that of free ligand mbbz. Polymer 5 with square pyramid geometry (τCu1, 0.069) implies that there is strong antiferromagnetic interactions between two adjacent Cu1C and Cu1, and the magnetic interactions are mainly transferred by the bridging N,N-triazole ligands.Five polymers have been synthesized and characterized. Polymer 1 possesses a 2-fold interpenetrating three-dimensional framework. Polymers 2–5 exhibit the 2D structures. The fluorescence properties of 1–5 are studied. Magnetic properties of 5 are also investigated.

•Polymers 1–4 exhibit 1-D double helical or double chain structures.•Influence of anions on complex structures containing mbbz ligand was discussed.•Various weak interactions are discovered and expand 1–4 to 3-D supramoleculars.•Their fluorescence properties are also investigated.Four one-dimensional (1-D) metal-organic polymers based on methylene-bis(1,1′-benzimidazole)(mbbz), namely, {[Hg(mbbz)(SCN)2]·1/3H2O}n (1), [Co(mbbz)(Cl)2]n (2), {[Co(mbbz)(SO4)]·CH3OH}n (3) and {[Zn(mbbz)(SO4)]·CH3OH}n (4) have been successfully synthesized and structurally characterized. Single-crystal X-ray diffraction reveals that polymers 1 and 2 exhibit interesting 1-D double helical chain structures, while polymers 3 and 4 are 1-D double chain structures due to the bridging effect of mbbz ligands and sulfate anions. These polymers containing the mbbz-based ligand have a high degree of dependence on the corresponding counter anions. Furthermore, the fluorescence properties of the four polymers were also investigated in the solid state, showing the fluorescence signal changes in comparing with that of free ligand mbbz.

Three new complexes based on 1-tetrazole-4-imidazole-benzene (Tibz), namely, [Cd(Tibz)2(H2O)2]n (I), [Mn(Tibz)2(H2O)4] · 2H2O (II) and [Co(Tibz)2(H2O)4] · 2H2O (III) have been synthesized through hydrothermal method and structurally characterized by element analyses, IR spectroscopy and single-crystal X-ray diffraction analyses (CIF files CCDC nos. 1443867 (I), 1443868 (II), 1443869 (III)). Single-crystal X-ray diffraction reveals that complex I is a 1D double-chain architecture, II and III are both mononuclear complexes. The results of single-crystal X-ray diffraction analyses indicate that the hydrogen bond and π··· π stacking exist in the complexes, which make great contribution to the stabilities of complexes I–III. The fluorescent properties of these complexes have also been studied in the solid state at room temperature.

•The self-assembly of PbAc2 with H2btapca affords different crystal structures.•Varying the ratio of mixed reaction solvents•Novel discrete cage structure•Enhanced fluorescence compared free ligandBy varying the ratio of mixed reaction solvent, the reactions of PbAc2 with N,N′-bis(1,3,4-thiobiazolyl)-2,6-pyridyldicarboxamide (H2btapca) afford two different crystal structures: a novel discrete hexanuclear cage of formula [Pb6(btapca)6]·(H2O)2 (1) and a 1-D double-chain polymer [Pb2(btapca)2(H2O)2]n (2). Fluorescence investigations reveal that both complexes display enhanced emissions in contrast to the free ligand H2btapca.A discrete hexanuclear cage of [Pb6(btapca)6]·(H2O)2 and a 1-D double-chain polymer [Pb2(btapca)2(H2O)2]n have been assembled by the reactions of PbAc2 with N,N′-bis(1,3,4-thiobiazolyl)-2,6-pyridyldicarboxamide (H2btapca) under different mixed reaction solvents. Both complexes have enhanced fluorescence in contrast to the free ligand.