ABSTRACT
By regulating the solvent used for synthesis, two porous Ni-MOFs, namely {[Ni3(BTC)2(TPT)2/3(H2O)4.08(MeOH)0.92]·2DMF·0.5H2O·0.5MeOH}n (1) and {[Ni3(BTC)2(TPT)2(H2O)6]·6DMF}n (2) (H3BTC = 1,3,5-benzenetricarboxylic acid, TPT = 2,4,6-tris(pyridin-4-yl)-1,3,5-triazine, DMF = N,N-dimethylformamide, and MeOH = methanol) were obtained. Compound 1 reveals a rigid 3D framework, while compound 2 shows a flexible 3-fold interpenetrated framework. Compound 1 exhibits a selective adsorption of CO2 due to the sieving effect of the rigid framework containing two types of cages with small apertures. Noteworthily, the flexible compound 2 displays an obviously guest-induced structural transformation. The desolvated compound 2 reveals a much higher capacity toward CO2 and n-C4H10 than those of N2 CH4, C2H6 and C3H8.
ABSTRACT
By simply modifying the expansion of ligand tether length, two Cd(ii) metal-organic frameworks have been constructed from linear tetranuclear and trinuclear cadmium clusters, respectively, which present an unprecedented 10-connected uninodal bct net.
ABSTRACT
In our continuing efforts to explore the effects of ligand modifications on the structures and properties of their metal complexes, we studied the in situ [2 + 3] cycloaddition reactions of benzonitrile, o-phthalodinitrile, 3-cyanobenzoic acid, 4-cyanobenzoic acid with NaN(3) in the presence of Zn(II) and/or Co(II) salts under hydrothermal conditions, and obtained four new Co(II)-doped Zn(II)-tetrazole-benzoate coordination polymers with the formula of [Co(x)Zn(1-x)(L(m))(y)](n) [5-phenyl-1H-tetrazole (HL(1)) for 1, 2-(1H-tetrazol-5-yl)benzoic acid (H(2)L(2)) for 2, 3-(1H-tetrazol-5-yl)benzoic acid (H(2)L(3)) for 3, and 4-(1H-tetrazol-5-yl)benzoic acid (H(2)L(4)) for 4]. The structure of 1 shows a classical diamondoid net, while 2 and 3, take 2D layer structure with (4.6(2))(4.6.4.6) topology and 3D SrAl(2) topology, respectively. The structure of 4 exhibits a four-connected 3D network with rare non-diamondoid 6(6) topology. The coordination modes of the center metal and the ligands in the four complexes are almost the same, being tetrahedral or four-connected, but their topologies are quite different. Thus, the four structurally related ligands allow analysis of the effects of the disposition of a second functional carboxylate group on an aromatic ring and the twist angles of the carboxylate and tetrazoyl out of the plane of the aromatic ring on the overall structural topology of their complexes. Interestingly, the Co(II) ions were doped into the Zn(II) complexes, as confirmed by their macroscopical colors, inductively coupled plasma (ICP) analysis and UV-visible spectra. In addition, the photoluminescence of the four complexes in the solid state at room temperature was briefly studied.
