Structural Design And Characterization Of New Metal Organic Frameworks

The characters of the materials are related to the constructions. In this paper, with the purpose of designing and synthesis new metal organic frameworks, we did lots of works on synthesis and characterizing. As most of synthetic reactions, template has been revealed as important factor that goven the structure, so does the MOFs. In this paper, a new two-dimensional metal organic framework is synthesized and characterized. The encapsulated chloride anions organize a collection of building units into a novel mixed-ligand metal organic supramolecular assembly, indicating specific host-guest recognition. By constrast, the addition of F-,Br-,I-,PO4- anions only give out the coordination complexes with single ligand. Reactions of the Zn2+ ion with 1,2,4-benzenetricarboxylic acid have been investigated with emphasis on the facors that govern reaction results. And the sample is characterized by the elemental analysis, TGA, XPRD, IR, and luminescent data.In addition, the relations between the luminescence characters and constructions are also investigated.Ï€-Ï€stacking in the 2,4,6-tris(4-pyridyl)-1,3,5-triazine aromatic nitrogen-containing ligand and its metal-ligand complex Zn(TPT)2(H2O)4(OH)2 1 have been investigated by single-crystal X-ray diffraction analyses. The stacking mode of the ligand change from the offset conformation to a face-to-face perfect alignment with the coordination to the zinc centers. The structure features have correlated with their solid-state luminescence properties. With excited at 360nm, free TPT ligand gives a strong fluorescent emission at 455nm and the ligand-centered emission of the metal-ligand complex occurs at the same wavelength with lower emission intensity. The distance between the aromatic rings respond to the difference of the luminescence characters.Otherwise, the MOFs could become photochromic materials based on the interesting energy transition among the moleculars.Two new mixed-ligand metal organic frameworks Zn(TPT)(BTC)H2O and Zn3(TPT)(BTC)2(H2O)6 are also synthesized and characterized. Compared with the Zn3(TPT)(BTC)2(H2O)6, Zn(TPT)(BTC)H2O displayed strong photochromic phenomenon. As in Zn(TPT)(BTC)H2O, there is a un-coordinated atom N, and the charge distribution in TPT is imbalance. Contrarily, the charge distribution in Zn3(TPT)(BTC)2(H2O)6 is symmetrical, and the difference respond to the diversity of the photochromic characters. Post modification with pyridine in Zn(TPT)(BTC)H2O also has been investigated.