Four new rare earth gallosilicates, Rb 2REGaSi4O12 (RE = Y, Eu, Gd, and Tb, denoted as REGS-1), have been synthesized under high-temperature, high-pressure hydrothermal conditions and characterized by single-crystal X-ray diffraction. They are the first examples of rare earth gallosilicates that contain individually occupied tetrahedral Ga(3+) and Si(4+) centers. The unique structure is formed of two 1D and one 2D substructural units: unbranched achter single chains which are seldom observed in silicates, the PaCl 5-type infinite chains formed of edge-sharing REO7 petagonal bipyramids and the unprecedented mixed-anion double layers with the composition [GaSi4O12].
View Article and Find Full Text PDFWater molecules and terephthalic acid, respectively, exist as a self-assembled monolayer of cyclic (H2O)6 clusters and (TA)infinity chiral chains between the zincophosphate sheets (in blue wires); the irremovable template H3tren3+ ions (in purple wires) are dynamic and could translate back and forth on the sheets during the conversion of the supramolecule contained in one another.
View Article and Find Full Text PDFA nanoporous zinc gallophosphate framework, NTHU-4, possessing 14-ring channels, disordered rims, and two luminant analogues, NTHU-4Y and NTHU-4W, has been synthesized and characterized; NTHU-4Y is an intrinsic yellow phosphor, while NTHU-4W is a white phosphor. The unique tetrahedral framework can be excited by wavelengths longer than 254 nm to give intense yellow-to-white luminescence. Subtle changes in disorderliness were observed to be related to the distinct photoluminescence property.
View Article and Find Full Text PDFThe first metal carboxylatophosphate, NTHU-2, contains inorganic ZnHPO4 layers linked by BDC units (BDC = 1,4-benzene dicarboxylate or terephthalic anion); the three-dimensional anionic framework has large pores with the smallest diameter being 1.36 nm; N2 sorption isotherms reveal both micro- and mesoporosity; the new material is photoluminescent and disassembles in water wherein the discharged organic fragments form mixed crystals.
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