Facile water-stability evaluation of metal-organic frameworks and the property of selective removal of dyes from aqueous solution.

A facile and universal method was developed to evaluate the relative water stability of porous MOFs and morphological evolution was achieved by controlling the volume ratio of DMF and H2O. The relative water stability of the studied MOFs is in the order HKUST-1 > MOF-505 ∼ UMCM-150 > NOTT-101 > DUT-23(Cu) > [Zn2(BPnDC)2(DABCO)] ∼ [Cu3(TPTrC)2(DABCO)] > MOF-5. In addition, DUT-23(Cu) [Cu6(BTB)4(BPY)3] (H3BTB = 4,4',4''-benzene-1,3,5-triyl-tribenzoic acid, BPY = 4,4'-bipyridine) nanoparticles obtained with a volume ratio of DMF and H2O of 18 : 2 show excellent adsorption capacity for methylene blue (MB) (814 mg g(-1)) with high selectivity compared with methyl orange, rhodamine B, and acid chrome blue K dyes due to the size and the electrostatic repulsion effects in aqueous solution.

Morphology evolution and gas adsorption of porous metal-organic framework microcrystals.

A facile and controllable synthesis of porous framework [Cu3(L)2(DABCO)] (1) (H3L = 1,1':3,1''-terphenyl]-4,4'',5'-tricarboxylic acid; DABCO = 1,4-diazabicyclo[2.2.2]octane) microcrystals was realized with morphology evolution from a tetragonal plate to an elongated tetragonal bipyramid, and the particle size changes by tuning the volume ratio of mixed solvents of DMF and H2O. Interestingly, the exposed high-energy {103} crystal facet can be easily tuned by controlling the supersaturation through the increase of the solution concentration, resulting in the formation of spindle microcrystals. It was found that both H2O and HCl play important roles in the morphology evolution process. The gas adsorption properties were found to be dependent on the morphology of microcrystals, and the elongated tetragonal bipyramidal microcrystals show the largest BET surface area.

Imidazolate-bridged dicopper(II) and copper(II)-zinc(II) complexes of macrocyclic ligand with methylimidazol pendants: Model study of copper(II)-zinc(II) superoxide dismutase.

Two new homo- and hetero-dinuclear complexes, [Cu(2)L(im)](ClO(4))(3)4H(2)O (1) and [CuZnL(im)](ClO(4))(3)4H(2)O (2) (where Im=1H-1midazole and L=3, 6, 9, 16, 19, 22-hexaaza-6, 19-bis(1H-imidazol-4-ylmethyl)tricycle[22, 2, 2, 2(11,14)]triaconta-1, 11, 13, 24, 27, 29-hexaene) were synthesized and characterized as model compounds for the active site of copper(II)-zinc(II) superoxide dismutase (Cu(2)Zn(2)-SOD). X-ray crystal structure analysis revealed that the metal centers in both complexes exhibit distorted trigonal-bipyramid coordination geometry and the Cucdots, three dots, centeredCu and Cucdots, three dots, centeredZn distances are both 6.02A. Magnetic and ESR spectral measurements of 1 showed antiferromagnetic exchange interactions between the imidazolate-bridged Cu(II) ions. The ESR spectrum of 2 displays typical signals of mononuclear Cu(II) complex, demonstrating the formation of heterodinuclear complex 2 rather than a mixture of homodinuclear Cu(II)/Zn(II) complexes. pH-dependent ESR and UV-visible spectral measurements manifest that the imidazolate exists as a bridging ligand from pH 6 to 11 for both complexes. The IC(50) values of 1.96 and 1.57microM [per Cu(II) ion] for 1 and 2 suggest that they are good models for the Cu(2)Zn(2)-SOD.

Di-µ-chlorido-bis-(chlorido{2,2'-[3-(1H-imidazol-4-ylmeth-yl)-3-aza-pentane-1,5-di-yl]diphthalimide}copper(II)).

The centrosymmetric dinuclear Cu(II) complex, [Cu(2)Cl(4)(C(24)H(21)N(5)O(4))(2)], was synthesized by the reaction of CuCl(2)·2H(2)O with the tripodal ligand 2,2'-[3-(1H-imid-azol-4-ylmeth-yl)-3-aza-pentane-1,5-di-yl]diphthalimide (L). Each of the Cu(II) ions is coordinated by two N atoms from the ligand, two bridging Cl atoms and one terminal Cl atom. The Cu(II) coordination can be best be described as a transition state between four- and five-coordination, since one of the bridging Cl atoms has a much longer Cu-Cl bond distance [2.7069 (13) Å] than the other [2.2630 (12) Å]. In addition, the Cu⋯Cu distance is 3.622 (1) Å. The three-dimensional structrure is generated by N-H⋯O, C-H⋯O and C-H⋯Cl hydrogen bonds and π-π inter-actions [centroid-centroid distances = 3.658 (4) and 4.020 (4) Å].