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Syntheses, Crystal Structures And Properties Of Metal-organic Coodination Polymers Constructed From The 2-sulfosuccinate Ligand

Posted on:2012-12-18Degree:MasterType:Thesis
Country:ChinaCandidate:E L YangFull Text:PDF
GTID:2211330338968337Subject:Inorganic Chemistry
Abstract/Summary:
The construction of metal–organic coordination polymers is a hot topic in inorganic chemistry, material chemistry, and solid state chemistry. The intense interest in these materials is driven by their intrinsic architectural beauty and aesthetically pleasing structures, as well as potential applications such as gas adsorption and separation, heterogeneous catalysis, drug carrier, photoelectron and molecular magnets. How to control the molecular architectures and the properties of functional metal–organic coordination polymers remains a challenge for the chemist. The choice of the organic ligands plays a vital role in the construction of metal–organic coordination polymers with desired properties and diverse strucutres. The combination of the bifunctional sulfonate-carboxylate ligands with various coordination modes with metal ions can produce metal–organic coordination polymers with diverse structures and interesting properties. Furthermore, the bifunctional sulfonate-carboxylate ligand can exhibit discriminative coordination abilities to different metal ions because it possesses two different kinds of functionalities. The carboxylate group favors transition metal ions in coordination, whereas the sulfonate group can easily coordinate to alkali metal ions, which will be described in compounds 4, 5, 7, 8, and 9.In this thesis, nine metal–organic coordination polymers from 2-sulfosuccinic acid (H3SS) ligands and metal ions the have been synthesized. These compounds are [Co3(SS)2(H2O)6]n (1), [Mn3(SS)2(H2O)6]n (2), [Ni3(SS)2(H2O)6]n (3), [Na2NiSS)2(μ2-H2O)2(H2O)2]n (4), [Na2Co2(SS)2(μ2-H2O)2(H2O)2]n (5), {[Pb3(SS)2(H2O)2]H2O}n (6), [Na4Zn(SS)2(H2O)4]n (7), {[Na2Zn3(μ3-OH)2(SS)2 -(H2O)4]}n (8), {[Na2Cu2(SS)2(μ2-H2O)2(H2O)4(2,2′-bpy)2)]}n (9) (2,2′-bpy is 2,2′-bipyridyl). These complexes were characterized by single-crystal X-ray diffraction, IR spectroscopy and thermogravimetric analysis (TGA). The fluorescent and magnetic properties of some compounds are investigated. We have discussed the effect of various factors including the effect of the anion of the metal salt, solvent, and molar ratio of metal and ligand on the final structures.The thesis is composed of five parts:The introduction for coordination chemistry and metal–organic coordination polymers is presented in first chapter. The latest research progress on metal–organic coordination polymers based on the carboxylate ligands, sulfonate ligands, and sulfonate-carboxylate ligands are reviewed in Chapter 1.The second chapter deals with the syntheses of the nine metal–organic coordination polymers based on 2-sulfosuccinic acid ligand and metal ions. Chapter 3 describes the crystal sructures of these compounds. Compound [Co3(SS)2(H2O)6]n (1) is a two-dimensional (2D) layered structure based on the centrosymmetric mononuclear [Co(SS)2]4- units where the two SS3- ligands chelate a cobalt ion , which are linked by the other type of the cobalt ions to give the 2D layer. The 2D layers are further linked by the hydrogen bonds between the coordinated water molecules and carboxylate and sulfonate oxygen atoms to give a three-dimensional (3D) supramolecular franework. Compounds [Mn3(SS)2(H2O)6]n (2), [Ni3(SS)2(H2O)6]n (3) and [Co3(SS)2(H2O)6]n (1) are isomorphous. Compound [Na2Ni2(SS)2(μ2H2O)2(H2O)2]n (4) features a 3D framework containing the the 2D anionic [Ni2(SS)2]2- layer based on the centrosymmetric mononuclear [Ni(SS)2]4- units where the two SS3- ligands chelate a nickel ion. The 2D anionic [Ni2(SS)2]2- layers are charged with sodium ions and linked by the sodium ions to form the final 3D structure. Compounds [Na2Ni2(SS)2(μ2H2O)2(H2O)2]n (4) and [Na2Co2(SS)2(μ2H2O)2(H2O)2]n (5) are isomorphous. Compound {[Pb3(SS)2(H2O)2]H2O}n (6) has a 3D framework where the lead ions are bridged by the SS3- ligands. There are two independent SS3- ligands with different coordination modes in this compound. [Na4Zn(SS)2(H2O)4]n (7) has a 2D anionic [NaZn(SS)2]3- layers based on the [Zn2(SS)2]2- macrocycles units where two SS3- ligands bridge two zinc ion. In this compound, the 2D anionic layers are linked by sodium ions in various manners to generate a 3D architecture. Compound {[Na2Zn3(μ3-OH)2(SS)2(H2O)4]}n (8) contains a 2D anionic [Zn3((μ3-OH)2(SS)2]2- layer based on the centrosymmetric mononuclear [Zn(SS)2]4- units, which are linked by the other type of zinc ions andμ3-hydroxy groups to form the 2D layer. The adjacent 2D layers are further bridged by the sodium ions to give a 3D structure. Compound {[Na2Cu2(SS)2(μ2H2O)2(H2O)4(2,2′-bpy)2)]}n (9) has a 1D structure based on the [Cu2(SS)2(μ2–H2O)2(2,2′–bpy)2]2- macrocycles units where two SS3- ligands bridge two copper ions. The netural 1D structures are bridged by the hydrogen bonds to give a 2D layered structure, which is further linked by theπ–πinteractions between the pyridyl rings of the adjacent 2,2′-bpy ligands to generate a 3D supramolecular structure.The physical properties such as thermal stabilities, fluorescent and magnetic properties of these compounds are investigated in Chapter 4. A brief conclusion and an outlook on this work are presented in the chapter 5.
Keywords/Search Tags:metal–organic coordination polymer, 2–sulfosuccinate, crystal structure, magnetic or fluorescent properties
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