Synthesis And Characterization Of Metal-Organic Frameworks Based On Tetra-carboxylate Ligand

Metal-organic frameworks (MOFs) is a new type of porous materials, MOFs own many advantages over traditional porous materials, such as high surface area, adjustable pore sizes, abundant structure topologies and so on, which makes it has great potential applications in gas adsorption and separation, luminescence, drug delivery. MOFs are connected by organic ligand and mono-nuclear, bi-nuclear or multi-nuclear inorganic SBUs. So by designing different organic ligands with functional groups (such as cooh-, nitro and sulfonic acid groups.) or choosing a different metal center, not only the orientation synthesis of MOFs can be realized, but also MOFs with different function abilities can be achieved. In this dissertation, three new tetra-carboxylates ligands and their corresponding MOFs were designed and synthesized. Details are presented as below:1. Three tetra-carboxylates ligands, H4La, H4Lb and H4Lc (H4La=2,2’-((6-chloro-1,3,5-triazine-2,4-diyl) bis(azanediyl)) diterephthalic acid, H4Lb =5,5’-((6-chloro-1,3,5-triazine-3,4-diyl)bis(azanediyl)) diisophthalic acid and H4Lc=2,2’-((6-(piperazin-1-yl)-1,3,5-triazine-2,4-diyl) bis(azanediyl)) diterephthalic acid) were designed, synthesized and characterized.2. Through the reactions of the ligands and transition metal ions, four new MOFs were prepared. Of these one compound [Cd2La(H2O)2]·2.5DMSO·2H2O (1) is based on H4La. two compounds [Cd2Lb(H2O)2DMF]·7DMF·H2O (2) and (H3O)[Cd4.5(Lb’)2(H2O)3]-13.5DMSO (3) are based on H4Lb, one compound (Me2NH2)5[Zn6(μ3-SO4)4(HLc)3]·10DMF·3H2O (4) is based on H4Lc.1 exhibits a 2D (3,3)-connected neutral framework with fes topology.2 displays a 3-fold integration 3D neutral framework with lvt-a topology.3 displays a 3D anionic framework with a new topology.4 bears a 3D framework with half double-walls based on 4-connected Lc3-and 4-connected{Zn3(SO4)2(CO2)6} MBB. Compound 4 can adsorb and release iodine, after being immersed in the cyclohexane solution of I2, which could be associated with a maximum of 2.2 I2 being adsorbed per formula unit of 4’.In addition, the delivery of I2 in ethanol increases linearly with time.4 exhibits strong photoluminescence in DMF suspensions, and its luminescence could be efficiently and selectively quenched by a series of nitroaromatics and dinoseb. For a-Nitronaphthalene and Dinoseb, the Stern-Volmer binding constants (KSv) is respectively 803.8668 and 4125.8198.