Syntheses, crystal structures and UV-visible absorption properties of five metal-organic frameworks constructed from terphenyl-2,5,2',5'-tetracarboxylic acid and bis(imidazole) bridging ligands.

The solvothermal reactions of terphenyl-2,5,2',5'-tetracarboxylic acid (H4tptc) and transition metal cations (Ni(II), Mn(II)) afford five novel coordination polymers (CPs) in the presence of four bis(imidazole) bridging ligands (1,3-bimb = 1,3-bis(imidazol-1-ylmethyl)benzene, 1,4-bmib = 1,4-bis(2-methylimidazol-1-ylmethyl)benzene, 4,4'-bibp = 4,4'-bis(imidazol-1-yl)biphenyl, 4,4'-bimbp = 4,4'-bis(imidazol-1-ylmethyl)biphenyl), namely, [M(tptc)(0.5)(1,3-bimb)(H2O)]n (M = Ni for 1, Mn for 2), {[Ni(tptc)(0.5)(1,4-bmib)]·0.

A highly photocatalytic polyoxomolybdate compound constructed from novel-type triple helix {Mo4O12}n chains and copper(I)-organic nets.

A novel-type 3D polyoxomolybdate-organic framework, {[Cu3(H3tpb)2(tpb)(Mo4O12)]·4H2O}n (1, H3tpb = 1,3,5-tri(1H-pyrazol-3-yl)benzene), was prepared and characterized by elemental analysis, IR spectroscopy, and luminescence analysis. Single-crystal X-ray diffraction analysis reveals that novel neutral triple helix {Mo4O12}n chains are encased in bowl-like 2D [Cu3(H3tpb)2(tpb)]n intervals via bond interactions between terminal oxygen atoms and cations of Cu(I), leaving an unprecedented (3,3,5,8)-connected (3·4·6(8))3(3(6)·4(6)·8(6)·9(6)·10(4))(4(3))2(6(3)) topology. Moreover, compound 1 exhibits remarkable photocatalytic activities for decomposition of methylene orange (MO), methylene red (MR), methylene blue (MB), methylene violet (MV), and rhodamine B (RhB) under UV light.