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Two novel complexes, {[Cd 3 (L) 2 (H 2 O) 2 ]·(H 2 O) 4 } n (1) and {[Mn(HL)(H 2 O) 2 ]·(H 2 O)} n (2), which are synthesized by the reaction of 3-(2, 4-dicarboxyphenyl)-4-carboxypyridine ligand with cadmium and manganese metal ions under the solvothermal method. The complex 1 is a 3D framework based upon trinuclear [Cd 3 (μ 2 -COO) 4 (μ 1 -COO) 4 (N) 2 ] SBUs, and the complex 2 is a one-dimensional metal oxygen chain based upon binuclear [Mn 2 (μ 2 -COO) 2 (μ 1 -COO) 2 (N) 2 ] SBUs. The solid fluorescence analysis of complex 1 reveals that the emission peak of 451 nm when its excitation peak is 336 nm. The fluorescence detection experiments of complex 1 showed that Fe3+, Cr 2 O 7 2− and CrO 4 2− can effectively to be detected. Furthermore, their limits of detection are 1.47 × 10−3 M, 1.31 × 10−3 M and 1.25 × 10−3 M, respectively. It has good recovery properties as a potential multifunctional fluorescence sensor. Besides, the quenching mechanism of fluorescence sensing is also discussed. In addition, the magnetic studies of complex 2 show strong antiferromagnetic interactions between its neighboring Mn(II) ions. [Display omitted] • Two novel stable complexes were constructed based on particular trinuclear and binuclear metal clusters. • Complex 1 shows high selectivity and sensitivity to detect Fe3+, Cr 2 O 7 2− and CrO 4 2− ions with low detection limit. • Complex 2 possesses antiferromagnetic interaction between its Mn (II) ions. [ABSTRACT FROM AUTHOR]

A new metal-organic framework, {[Co1.5(μ2-OH)(L)(bipy)0.5] ·0.5DMF}n (1) (H2L = (4,4'-(hexafluoroisopropylidene)bis(benzoic acid) and bipy = 4,4'-bipyridine), has been prepared under solvothermal conditions using flexible dicarboxylate and rigid N-donor co-ligands in the presence of Co(II) ion as the building blocks. The x-ray single-crystal diffraction analysis indicates that 1 possesses a three-dimensional (3D) layer-pillar structure with one-dimensional (1D) metal-carboxylate chain. The Co(II) ions are bridged by L2- to generate a two-dimensional (2D) sheet, which is further pillared by bipy into a 3D framework with {44.62}{45.65}2 topology. In addition, the variable-temperature magnetic susceptibility measurement indicates there exists an anti-ferromagnetic behavior between in the Co(II) ions of 1. [ABSTRACT FROM AUTHOR]

• Two novel 2D MOFs based on diverse metal-oxygen chains with high open metal sites. • Zn-MOF possesses good selectivity and sensitivity to detect Fe3+ and Cr 2 O 7 2− ions with low detection limit. • The variable-temperature susceptibility of Mn-MOF indicates antiferromagnetic interaction between the Mn(II) ions. In this paper, two novel two-dimensional MOFs were synthesized by solvothermal reaction of 2,4-di(2′,5′-dicarboxylphenyl)benzoic acid ligand and Zn(Ⅱ) and Mn(Ⅱ) metal ions: {[Zn 2 (HL)(H 2 O)(DMF) 2 ]·(H 2 O)·(DMF)} n (1), {[Mn 2 (HL)(H 2 O)(DMF) 2 ]·(H 2 O)·(DMF)} n (2). Complexes 1 and 2 are unique two-dimensional skeletons with particular metal-oxygen chains in their structures. The solid-state luminescence spectrum of complex 1 shows that its maximum emission peak is 448 nm. Further fluorescence studies of complex 1 show that it can efficiently detect Fe3+ and Cr 2 O 7 2− in aqueous solution with a detection limit of 4.1 × 10−4 M and 2.7 × 10−4 M respectively, and has good recycling performance, so it is a potential bifunctional fluorescent probe material. The mechanism of fluorescence sensing quenching was also investigated in detail. Furthermore, magnetic studies have shown that there is an antiferromagnetic interaction between Mn(II) ions of complex 2. [Display omitted] [ABSTRACT FROM AUTHOR]

A new porous metal-organic framework, namely [Co 3 (L)(OH) 2 (H 2 O) 4 ]·NMP·3H 2 O (1), has been yielded by using Co(II) and rigid V-shaped 2,6-di(2′,5′-dicarboxylphenyl)pyridine (H 4 L). The structure analysis revealed that MOF 1 is a three-dimensional (3D) porous framework with 1D [Co 3 (OH) 2 ] n ferromagnetic chains. The gas sorption measurements and the IAST analysis indicated MOF 1 has a relatively high selectivity for C 2 H 6 and CO 2 over CH 4. The magnetic properties indicated that MOF 1 has the ferrimagnetic and slow magnetic relaxation behavior, giving an interesting single-chain magnet behavior with an effective energy barrier of 15.82 K. A new 3D porous MOF 1 has been successfully synthesized. Gas sorption tests showed that MOF 1 has a relatively high adsorption capacity and selectivity for C 2 H 6 and CO 2 over CH 4. And also, MOF 1 displays the ferrimagnetic and slow magnetic relaxation behavior, giving an interesting single-chain magnet with an effective energy barrier of 15.82 K. Image 1 • The rigid V-shaped nitrogen heterocyclic carboxylic acid ligand 2,6-di(2′,5′-dicarboxylphenyl)pyridine(H 4 L) and Co(II) ions was selected as the building units to build porous crystalline MOF. • Structure analysis revealed that MOF 1 is a three-dimensional (3D) porous framework with 1D [Co 3 (OH) 2 ] n ferromagnetic chains. • Gas sorption measurements and the IAST analysis showed that MOF 1 has the higher adsorption selectivity for C 2 H 6 and CO 2 over CH 4. • Magnetic properties indicated that MOF 1 has the ferrimagnetic and slow magnetic relaxation behavior. [ABSTRACT FROM AUTHOR]