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Eu(III)–Sr(II)–K(I) and Tb(III)–Sr(II)–K(I) heterotrimetallic metal-organic frameworks with 2,4,6-pyridinetricarboxylic acid have been synthesized under hydrothermal conditions. The complexes are isomorphic and both in triclinic space groupP-1. The ligands bond with three metal ions with two coordination modes. One connects seven metal ions and the other connects eight metal ions. IR spectra, thermal analysis, and photoluminescent properties have been studied. The results display strong characteristic emissions of Eu(III) or Tb(III) ions with excitation of ultraviolet radiation. [ABSTRACT FROM PUBLISHER]

Three coordination polymers, [Ag4(bpy)3(pztc)] n (1), {[Ag6(bpy)2(pztc)(CN)2] · 2.6H2O} n (2), and {[Ag2(H2pdtc)(bpy)2] · 3H2O} n (3) (H4pztc = pyrazine-2,3,5,6-tetracarboxylic acid, H4pdtc = pyridine-2,3,5,6-tetracarboxylic acid, bpy = 4,4′-bipyridine), have been synthesized and characterized by elemental analysis, IR spectra, thermogravimetric analysis, UV spectra, fluorescent spectra, and single-crystal X-ray diffraction. Complex 1 displays a 3-D network with infinite channels of about 6.4 × 3.1 Å2 along the a-axis. The structure of 1 can be simplified as a 3,4,4-connected framework. Complex 2 displays a 3-D network and can be simplified as a 6,6-connected pcu framework. Complex 3 shows a 1-D chain structure and the chains form a 2-D layer structure by hydrogen bonds. Complexes 1–3 emit intense fluorescence at around 500 nm on excitation at 340 nm, 320 nm, and 340 nm, respectively. [ABSTRACT FROM AUTHOR]