Synthesis, Structures And Properties Of Novel Supramolecular Coordination Polymers Generated From 5-Nitroisophthlate Ligand

A great deal of effort has been invested in the design and synthesis of coordination polymers (metal-organic frameworks, MOFs) in supramolecular and materials chemistry because of their intriguing network topologies and promising applications in fields such as catalysis, ion exchange, gas storage, selective adsorption, optics and magnetic devices. Up to now, numerous one-, two- and three-dimensional coordination polymers have been synthesized by choice of appropriate metal ions and versatile bridging organic ligands. In addition to coordinative covalent bonding which is most important in constructing coordination polymer, hydrogen bonding,π-πstacking interaction and other weak intermolecular interactions have attracted considerable interest in the construction of supramolecular architectures. In this paper, we report the preparations, crystal structures and properties of sixty-two kinds of coordination polymers generated from 5-nitroisophthlate ligand, in order to study on the effect factors (metal ions, organic ligand, pH value, temperature and templated etc.) of these reactions.1. In chapter two, we report three series of lanthanide-carboxylate frameworks (MOF-S1-S23).First, ten 2-D lanthanide coordination frameworks (MOF-S1-S10) have been synthesized through the reaction of lanthanide nitrate salt and H2NIPH in the presence of 4,4'-bipy molecules. In MOF-S1-S2, the coordination sheets are composed of polynuclear helical-like chains {---[Ln4(CO2)9]—(O-C-O)3---}n. MOF-S3-S5 are extremely similar in 2D structure, in which Ln atoms are bridged into rod-shaped chains [---Ln(CO2)2---]n by carboxylate groups. For MOF-S6-S7 and MOF-S8-S10, the coordination layers are built from 1D zig-zag chains {[Ln2(CO2)2]—(O-C-O)2---}n and [---Ln(CO2)2---]n, respectively. All of these coordination layers alternately stack with the organic layers of 4,4'-bipy resulting in the formation of 3D networks based on hydrogen bonding interactions. The presence of 4,4'-bipy molecules in the reaction systems promotes the generations of layered Ln coordination frameworks. MOF-S7 exhibits strong red emission, which suggest that it may be an efficient solid emitting material.Secondly, nine lanthanide coordination polymers (MOF-S11-S19) have been synthesized via the reaction of lanthanide nitrate salts, H2NIPH and 1,10-phenanthroline (phen). Single-crystal X-ray diffraction analysis reveals that different coordination modes of the organic ligand and different coordination numbers of lanthanide atoms make remarkable topologies structures which are constructed from paddle-wheel building blocks. MOF-S11-S13 possess 1D double-stranded loop-like chains structures that are further interlinked via hydrogen bonds resulting in a 3D supramolecular networks. MOF-S14-S15, S16-S17 have different 2D layer structures which are further constructed to form 3D supramolecular networks by hydrogen bonds. MOF-S18 and MOF-S19 are isostructual and have 3D framework with pcu topology. The MOF-S18 exhibits interesting luminescence properties.Thirdly, we choose lanthanide nitrate salts, SO42- (or NO3-), H2NIPH as reaction system at hydrothermal condition and have obtained four coordination polymers (MOF-S20-S23). MOF-S20-S22 are isostructural and exhibit 3D framework with novel 3,4,5,10-connected nets topology. MOF-S23 displays a 2D framework which is constructed from 1D chains.2. In chapter three, we describe the design and synthesis of three series novel 3d-4f heterometallic coordination polymers.First, two series heterometallic Ln–Cu (Ln = Gd3+, Nd3+, Sm3+, Eu3+, Tb3+, Dy3+, Ho3+ and Er3+) coordination frameworks (MOF-S24(a,b)-MOF- S38(a,b)) have been successfully synthesized and exhibit reversible single-crystal-to-single- crystal transformation behavior based on dehydration and rehydration process. The variable coordination numbers (Cu2+ (from 4 to 6) and Ln3+ (from 8 to 9)) and porous structures are responsible for the reversible crystalline transformation reported in this study. The crystal transition is companied by a remarkable change in color suggesting the potential application in sensing devices. Hopefully, for the frameworks with substitution-active metal sites, the change of coordination environment can affect their metal orbital configuration that may lead to the electronic and spin control in MOFs. To the best of our knowledge, this may be the first example of single-crystal-to-single-crystal dynamic structural changes of 3d-4f mixed metal-based coordination polymers.Secondly, four La-Cu, Ce-Cu and Pr-Cu heterometallic coordination polymers (MOF-S40-S43) have been hydrothermally synthesized. In MOF-S40, the infinite zig-zag rod is composed of alternating nine-coordinated La(III), six-coordinated Cu(II) and four-coordinated Cu(II) metal centers. In MOF-S41, the infinite line-like rod is generated from a pair of edge-sharing LaO9 polyhedral alternating with edge-sharing CuO6 polyhedron. In MOF-S42, [Ce2O16(CO2)2] cores and [CuO4] cores are interconnected by carboxyl groups into infinite zig-zag rod. The benzene units of the NIPH ligands connect each rod to four neighboring rods, generating pcu type rod packing. While MOF-S43 and MOF-S24a are isostructural.3. In chapter four, using the transition metal, H2NIPH and accessorial ligands (pyridine, benzimidazole, imidazole, 4,4'-bipy), fifteen novel supramolecular coordination polymers (MOF-S44-S58) have been prepared and characterized.First, four coordination polymers (MOF-S44-S47) based on polynuclear copper cluster building blocks have been synthesized and characterized. For MOF-S44, a two-dimensional framework is constructed from infinite polynuclear copper chains linked together by NIPH ligands. MOF-S45 contains unprecedented pentanuclear [Cu5(μ3-OH)2(μ2-H2O)2] building units that and joined through NIPH ligands to generate a three-dimensional structure. MOF-S46 exhibits novel one-dimensional band structure consist of hexanuclear [Cu6(μ3-OH)4(μ2-H2O)2] building units linked by NIPH ligands. MOF-S47 not only possesses a three-dimensional structure, but also contains mixture oxidation stat copper centers. The antiferromagnetic coupled interactions exist in MOF-S45 and S46 upon decreasing temperature.Secondly, using pyridine, benzimidazole and imidazole as terminal ligands and NIPH dianion as bridging ligand, we have synthesized eleven metal-organic coordination polymers (MOF-S48-S58). All of these compounds possess hydrogen-bonded three-dimensional networks with different one-dimensional chains motifs (zig-zag chain, line-like chain and double-stranded loop-like chain). The structural investigation of these compounds indicates that the variations of coordination modes of organic ligands are important to influence on the structural variations and 1D chain structural packing mainly dependents on the hydrogen bonds andπ-πinteractions. The temperature-dependent magnetic susceptibilities of MOF-S52 have been measured.4. In chapter five, four novel zinc-polycarboxylate coordination polymers (MOF-S59-S62) have been synthesized. MOF-S59 possesses diamond topology of the four-connected three-dimensional structure. MOF-S60 exhibits bct topology of a three-dimensional framework. MOF-S61 is two-dimensional layer. Furthermore, MOF-S62 is also two-dimensional framework with novel polynuclear building block. MOF-S59-S61 display novel emission properties. For MOF-S60, organic molecules can be removed and reintroduced again. To our knowledge, these are the rare examples that anionic metal-organic open frameworks with protonated DAA molecules as template residing in the channels and playing as structure directing agent, space-filling and charge balancing roles.In conclusion, we have designed and synthesized sixty-two kinds of novel supramolecular coordination polymers generated from 5-nitroisophthlate ligand. These coordination polymers have been characterized by elemental analysis, IR and UV-vis spectra, TGA analysis, and single crystal X-ray diffraction. The luminescent and magnetic properties of some compounds have been measured.