No description available.

This study focussed on two copper(II)-containing metal-organic frameworks (MOFs): Cu2Na(OH)B4C•7H2O and Cu2¼(OH)½B4C•8H2O (B4C = 1,2,4,5- benzenetetracarboxylate). They are both covalent, three-dimensional metalorganic framework polymers containing voids filled with water molecules. Both were characterised by elemental analysis, infrared spectroscopy, X-ray powder diffractometry (both in situ and regular), thermogravimetric analysis, differential scanning calorimetry and X-ray photoelectron spectroscopy. These two MOFs are essentially identical, with the only difference being the substitution of sodium by copper at every 4th site (disordered throughout the crystal). The guest inclusion properties of both MOFs were studied and compared. Although both structures collapse on dehydration, it was observed that Cu2Na(OH)B4C•7H2O is able to take up signifcant amounts of water, methanol and ethanol. All these processes are fully reversible. Car-Parrinello molecular dynamics studies suggest that it is a strong interaction between the oxygen atoms on these molecules with the sodium cation of the MOF that is responsible for this signifcant uptake. In contrast, Cu2¼ (OH)½ B4C•8H2O, the MOF without a sodium cation, did not demonstrate any methanol or ethanol uptake, but was able to take up some water. The uptake of water, however, is not a fully reversible process. The absence of sodium likely results in insuffcient energy to draw methanol and ethanol into the framework, while a subtle rotation of a carboxylate group on dehydration decreases the ability of the framework to form hydrogen bonds, thus reducing the ability to take up water. A series of hydrothermal syntheses were performed in order to develop a method of synthesis superior to the current gel-based synthesis that requires several months and has poor yields. The hydrothermal products were characterized by elemental analysis, infrared spectroscopy, X-ray powder diffractometry, thermogravimetric analysis and differential scanning calorimetry. It was shown that the MOF Cu2Na(OH)B4C•7H2O may be synthesised in almost 100% yield by using a temperature of 120°C over a period of 72 hours. It was not possible to synthesise Cu2¼ (OH)½ B4C•8H2O in a 100% yield - it was only obtained as a minor product.

Thesis (Ph. D.)--University of Canterbury, 2007. / Typescript (photocopy). Includes bibliographical references (leaves 158-163). Also available via the World Wide Web.

No description available.

This thesis describes the investigation of the coordination and supramolecular chemistry of three different types of pyridine-containing ligand with a selection of Ag(I), Cu(I), Cu(II) and Cd(II) salts. The ligand types are flexible and four-armed, rigid and four-armed and bent with two rigid arms. All the ligands also display the ability to form additional supramolecular interactions. Chapter one introduces supramolecular chemistry and crystal engineering and covers background on several areas of current interest in these fields. Network structures, both coordination polymers and hydrogen-bonded systems, are discussed and topological analysis as a method of describing and comparing network structures is introduced. An outline of the ligand design, choice of transition metals and anions is given. Chapter two provides a review of flexible four-armed pyridine-containing ligands and their use in coordination chemistry. The synthesis and characterisation of three flexible four-armed ligands 1,2,4,5-tetrakis(2-pyridylmethyl-sulfanylmethyl)benzene (2tet), 1,2,4,5-tetrakis(3-pyridylmethyl-sulfanylmethyl)benzene (3tet) and 1,2,4,5-tetrakis(4-pyridylmethyl-sulfanylmethyl)benzene (4tet) are given. The synthesis and characterisation of the Ag(I), Cu(II) and Cd(II) complexes formed with these three ligands are also given. The complex of [Cd(2tet)(NO₃)₄] was structurally characterised by X-ray diffraction and was found to be a discrete species. The complexes {[Ag₂(3tet)](ClO₄)₂}n̲, {[Ag₂(3tet)](PF₆)₂}n̲, {[Ag₂(3tet)](CF₃CO₂)₂}n̲, {[Ag₂(4tet)]-(ClO₄)₂�2MeCN�2CHCl₃}n̲, {[Ag₂(4tet)](PF₆)₂�6MeCN}n̲ and {[Ag₂(4tet)](ClO₄)₂-�3H₂O}n̲ were likewise structurally characterised by X-ray diffraction. All these complexes were three-dimensional coordination polymers. A comparison of the seven structures is given at the end of the chapter. Chapter three reviews rigid four-armed pyridine-containing ligands and their use in coordination chemistry. The preparation of the rigid four-armed ligand 2,3,4,5-tetrakis(4-pyridyl)thiophene (pyth) is given. The synthesis and characterisation of the Ag(I), Cu(I) and Cd(II) complexes formed with this ligand are also given. The complexes [Ag(pyth)](BF₄)�3MeCN�CH₂Cl₂}n̲, [Ag(pyth)](PF₆)�MeCN�CH₂Cl₂}n̲, [Ag(pyth)]-(CF₃SO₃)�2MeCN�CH₂Cl₂}n̲, [Cu(pyth)](PF₆)�MeCN�CH₂Cl₂}n̲ and [(Cu₂I₂)(pyth)]-(BF₄)�1/2CH₂Cl₂�H₂O}n̲ were structurally characterised by X-ray diffraction. The complex with CuI was a two-dimensional coordination polymer, and the other four complexes were three-dimensional coordination polymers. A comparison of the five structures is given at the end of the chapter. Chapter four begins with a review of rigid angular bridging ligands and their use in coordination and supramolecular chemistry. The preparation of the ligand bis(4-pyridyl)amine (bpa) is given. The structural arrangement of bpa in the solid state was determined by X-ray diffraction. Complexes of Ag(I), Cu(I), Cu(II) and Cd(II) formed with this ligand were synthesised and characterised. The complexes {[Ag(bpa)(MeCN)](CF₃SO₃)}n̲, {[Ag(bpa)](PF₆)�MeCN}n̲, {[Ag(bpa)](ClO₄)-�2MeCN}n̲, {[Ag(bpa)](ClO₄)}n̲, {[Ag(bpa)](NO₃)}n̲, [(Cu₂I₂)(bpa)₂]n̲, {[Cu(bpa)₂Cl₂]-�3DMF�3/2H₂O}n̲, {[Cd(bpa)₂(NO₃)(H₂O)](NO₃)}n̲, {[Cd(bpa)₂(SO₄)(H₂O)]�3H₂O}n̲, [Cd(bpaH)₂(SO₄)₂(H₂O)₂]�2MeCN and {[Cd(bpa)(SCN)₂]�1/5iPrOH}n̲ were structurally characterised by X-ray diffraction. All complexes with Ag(I) were one-dimensional coordination polymers, with two of them helical, the other three zigzag. Both complexes with Cu(I) and (II) were two-dimensional coordination polymers. One complex with CdSO₄ was discrete, with the bpa ligands mono-protonated, but all other three other Cd(II) complexes were three-dimensional coordination polymers. Seven of these complexes showed hydrogen-bonding interactions linking them together to form supramolecular structures of higher dimensionalities. A comparison of the twelve structures is given at the end of the chapter. Chapter five is a brief summary of the outcomes of this thesis.

Title from title page of PDF (University of Missouri--St. Louis, viewed Mar. 3, 2010). Includes bibliographical references.

This thesis describes the investigation of the coordination and supramolecular chemistry of three different types of pyridine-containing ligand with a selection of Ag(I), Cu(I), Cu(II) and Cd(II) salts. The ligand types are flexible and four-armed, rigid and four-armed and bent with two rigid arms. All the ligands also display the ability to form additional supramolecular interactions. Chapter one introduces supramolecular chemistry and crystal engineering and covers background on several areas of current interest in these fields. Network structures, both coordination polymers and hydrogen-bonded systems, are discussed and topological analysis as a method of describing and comparing network structures is introduced. An outline of the ligand design, choice of transition metals and anions is given. Chapter two provides a review of flexible four-armed pyridine-containing ligands and their use in coordination chemistry. The synthesis and characterisation of three flexible four-armed ligands 1,2,4,5-tetrakis(2-pyridylmethyl-sulfanylmethyl)benzene (2tet), 1,2,4,5-tetrakis(3-pyridylmethyl-sulfanylmethyl)benzene (3tet) and 1,2,4,5-tetrakis(4-pyridylmethyl-sulfanylmethyl)benzene (4tet) are given. The synthesis and characterisation of the Ag(I), Cu(II) and Cd(II) complexes formed with these three ligands are also given. The complex of [Cd(2tet)(NO₃)₄] was structurally characterised by X-ray diffraction and was found to be a discrete species. The complexes {[Ag₂(3tet)](ClO₄)₂}n̲, {[Ag₂(3tet)](PF₆)₂}n̲, {[Ag₂(3tet)](CF₃CO₂)₂}n̲, {[Ag₂(4tet)]-(ClO₄)₂�2MeCN�2CHCl₃}n̲, {[Ag₂(4tet)](PF₆)₂�6MeCN}n̲ and {[Ag₂(4tet)](ClO₄)₂-�3H₂O}n̲ were likewise structurally characterised by X-ray diffraction. All these complexes were three-dimensional coordination polymers. A comparison of the seven structures is given at the end of the chapter. Chapter three reviews rigid four-armed pyridine-containing ligands and their use in coordination chemistry. The preparation of the rigid four-armed ligand 2,3,4,5-tetrakis(4-pyridyl)thiophene (pyth) is given. The synthesis and characterisation of the Ag(I), Cu(I) and Cd(II) complexes formed with this ligand are also given. The complexes [Ag(pyth)](BF₄)�3MeCN�CH₂Cl₂}n̲, [Ag(pyth)](PF₆)�MeCN�CH₂Cl₂}n̲, [Ag(pyth)]-(CF₃SO₃)�2MeCN�CH₂Cl₂}n̲, [Cu(pyth)](PF₆)�MeCN�CH₂Cl₂}n̲ and [(Cu₂I₂)(pyth)]-(BF₄)�1/2CH₂Cl₂�H₂O}n̲ were structurally characterised by X-ray diffraction. The complex with CuI was a two-dimensional coordination polymer, and the other four complexes were three-dimensional coordination polymers. A comparison of the five structures is given at the end of the chapter. Chapter four begins with a review of rigid angular bridging ligands and their use in coordination and supramolecular chemistry. The preparation of the ligand bis(4-pyridyl)amine (bpa) is given. The structural arrangement of bpa in the solid state was determined by X-ray diffraction. Complexes of Ag(I), Cu(I), Cu(II) and Cd(II) formed with this ligand were synthesised and characterised. The complexes {[Ag(bpa)(MeCN)](CF₃SO₃)}n̲, {[Ag(bpa)](PF₆)�MeCN}n̲, {[Ag(bpa)](ClO₄)-�2MeCN}n̲, {[Ag(bpa)](ClO₄)}n̲, {[Ag(bpa)](NO₃)}n̲, [(Cu₂I₂)(bpa)₂]n̲, {[Cu(bpa)₂Cl₂]-�3DMF�3/2H₂O}n̲, {[Cd(bpa)₂(NO₃)(H₂O)](NO₃)}n̲, {[Cd(bpa)₂(SO₄)(H₂O)]�3H₂O}n̲, [Cd(bpaH)₂(SO₄)₂(H₂O)₂]�2MeCN and {[Cd(bpa)(SCN)₂]�1/5iPrOH}n̲ were structurally characterised by X-ray diffraction. All complexes with Ag(I) were one-dimensional coordination polymers, with two of them helical, the other three zigzag. Both complexes with Cu(I) and (II) were two-dimensional coordination polymers. One complex with CdSO₄ was discrete, with the bpa ligands mono-protonated, but all other three other Cd(II) complexes were three-dimensional coordination polymers. Seven of these complexes showed hydrogen-bonding interactions linking them together to form supramolecular structures of higher dimensionalities. A comparison of the twelve structures is given at the end of the chapter. Chapter five is a brief summary of the outcomes of this thesis.

This thesis describes the synthesis, characterisation and catalytic testing of multifunctional immobilised metal nanoparticle in metal-organic framework (MOF) materials. Combining the activity of metal nanoparticles with the porosity and Lewis acidity of metal-organic frameworks provides a single catalytic material which can perform multi-step reactions. Strategies to immobilise the metal nanoparticles within the metal-organic frameworks have been investigated. Immobilisation has been achieved by applying three different methodologies. First, deposition of metal nanoparticle precursors within mesoporous MOFs is discussed. Chapter 3 shows the effectivity of the double solvents deposition technique to achieve dispersed and small nanoparticles of around 2.7 nm. The best system combined Pd nanoparticles with MIL-101(Cr). This system was further investigated in tandem reductive amination catalysis, discussed in Chapter 4, to investigate the activity and selectivity provided by these multifunctional catalysts. Another immobilisation technique was performed by coating Pd decorated SiO2 spheres with a MOF layer. Using this technique, MOF was grown cyclically in solution, providing tuneable shell thicknesses of MOF on the metal nanoparticle decorated oxide spheres. While the homogeneity of the MOF shell needs more optimisation, it was determined that the surface charge on the spheres played an important role in the growth of MOF in the desired location. Finally, the third immobilisation technique is the core-shell growth of MOF on colloidal metal nanoparticles. Polymer-capped metal nanoparticles with well-defined shapes were synthesised and characterised. From here, the optimisation of conditions for core-shell growth of UiO-66 and MIL-100(Sc) were investigated. Conditions which provided the desired core-shell morphology were found for both MOF types. These materials were then subsequently used in tandem reductive amination catalysis and a more straightforward styrene hydrogenation. It was shown that the metal nanoparticles remain active catalysts within either MOF shell and the MOF shell stabilises the metal nanoparticle and acts as a Lewis acid catalyst.

Metal-organic frameworks (MOFs) are crystalline materials with metal ions covalently bonded to organic ligands. The ligands act as spacers often creating a porous structure with very high pore volume and surface area. MOFs are known for their robust structures, high porosity, and different chemical functionalities and are considered for applications in adsorptions, separations, catalysis and gas storage. This work focuses on the synthesis of new MOFs using copper compounds. Different types of carboxylate ligands were used for the synthesis. Two new copper-organic frameworks, [Cu3(pyz)(btc)] (1), and [(Cu3(btc))•xH2O] (2) (btc= benzene-1,3,5-tricarboxylate, pyz= pyrazine) have been synthesized using hydro/solvothermal methods and have been characterized using X-ray diffraction, IR, TGA, fluorescence and CHN analysis.

This work investigated the synthesis, characterisation and properties of known and novel scandium carboxylate Metal-organic Frameworks (MOFs). The first part reports the performance of these Sc-MOFs as Lewis acid catalysts. The porous MOF scandium trimesate MIL-100(Sc) and the scandium terephthalates such as MIL-101(Sc), MIL-88B(Sc) and MIL-68(Sc) (prepared as the Sc-analogue for the first time), and scandium biphenyldicarboxylate MIL-88D(Sc) were prepared and tested as Lewis acid catalysts. Chromium MIL-101 and MIL-100 and scandium-exchanged zeolites were prepared for comparison. Moreover, successful encapsulation of the phosphotungstate polyoxometalates (POMs) in the cavities of MIL-101(Sc) enhanced the stability of this material. These scandium and chromium MOFs, POM-MOF composites and scandium-exchanged zeolite were tested as heterogeneous catalysts in the carbonyl ene reaction between α-methyl styrene and ethyl trifluoropyruvate. This showed that MIL-100(Sc) was the best catalyst for this reaction, achieving a conversion of 99% to the desired product. The stabilized MIL-101(Sc) was also very active, but less selective for this reaction. Acetalisation of acetaldehyde was also studied, and in this reaction the isoreticular MOFs MIL-88(B) and MIL-88D(Sc) were the most active and selective catalysts. For this reaction, the activity of MIL-100(Sc) was low, which was attributed to reduce pore size and blockage. Functionalisation of the range of scandium terephthalates such as MIL-101(Sc), MIL-88B(Sc), MIL-68(Sc), Sc₂BDC₃,and MIL-53(Sc) particularly with –NH₂ groups, made up the second main part of this research. Solvothermal synthesis were performed at lower temperatures and using mixed solvents to synthesize these amino-terephthalate MOFs, often for the first time, and their adsorption properties were studied, particularly for the adsorption of CO₂. The synthesis of pure Sc₂(NH₂-BDC)₃ and Sc₂(Br-BDC)₃ was achieved for first time by a solvothermal route, lower temperatures, and mixed solvents. This approach yielded large crystals suitable for single crystal diffraction and microcrystal IR spectroscopy. Post-synthetic modification (PSM) of Sc₂(NH₂-BDC)₃ was explored by incorporation of NO₂-groups into the framework by solvent-assisted ligand exchange. The adsorption properties of functionalised and post-modified materials were compared with those of Sc₂BDC₃ and Sc₂(NO₂-BDC)₃ for methanol and hydrocarbons This study demonstrated that Sc₂BDC₃ and Sc₂(NH₂-BDC)₃ give the higher uptakes while the –Br and –NO₂ forms display shape selectivity for n-alkanes over iso-alkanes. Amino-functionalised MIL-53(Sc) was prepared for the first time using a mixed ligand approach, so that 10-20% of a second functionalised terephthalate ligand (NO₂, Br, -(OH)₂) was required for successful single phase synthesis in addition to amino-terephthalic acid. The materials were characterised using PXRD, TGA and gas adsorption, which confirms the samples show a range of behaviour for CO₂ adsorption. Notably, the `breathing´ behaviour is strongly dependent on the type of functionalisation. Finally, the exploratory synthesis of novel scandium MOFs, using isophthalic acid (IA) and its amino and nitro- derivatives, 2,5-furandicarboxylate (FDA) and the porphyrin tetra(carboxyphenyl)porphyrin (TCPP) as linkers was carried out and six novel materials were synthesized, three of which gave crystals large enough for their structure to be determined by single crystal diffraction. Further characterisation was carried out by PXRD, TGA and solid-state NMR. Some of these materials have been shown to be porous to CO₂ and N₂.