Syntheses Of Aromatic Acid With A Heterocyclic Ring Ligands And Ionothermal Sytntheses、Crystal Structures And Properties Of The Metal-organic Coordination Polymers

The metal-organic coordination polymers （MOCPs） do possess fascinatingstructure aesthetics and have potential applications in optics, catalysis, adsorption,electric conduction, molecular recognition, separation, etc. The study of the functionalMOCPs is one of the most active areas of chemistry community in very recent years.The methods for synthesis of the MOCPs are of important for achieving the functionalMOCPs. Ionic liquids （ILs） bearing the advantages of negligible vapor pressures,non-volatile, largerly stable temperature range, high thermal stability, widelyelectrochemical stability potential window, and designability, are a class of organicsolvents with high polarity and a preorganized solvent structure. Recently theionothermal synthesis has been employed to prepare crystalline solids, in which ILsparticipate as both solvent and structure-directing agent, resulting in interestingmaterials. ILs can be varied with different anions and cations to result in the diversityof the ILs, which leads to distinct topological structures of the material produced.In this thesis, we present the MOCPs constructed from metal ions such aszinc（Ⅱ）, cadmium（Ⅱ）, cobalt ion（Ⅱ）, copper ion（Ⅱ）, gadolinium(（ⅡI） ions et.al., andaromatic acid with a heterocyclic ring or aromatic acid as the organic ligandFortunately, nine new MOCPs were successfully obtained under ionothermalreactions. The structures of all the compounds have been characterized bysingle-crystal X-ray diffraction, IR spectroscopy, element analysis, thermal-gravityanalyses and topological structures have been performed on part of these compounds.We have discussed the effect of various factors including the effect of the species ofionic liquids, temperature, molar ratio of metal and ligand on the final structures.The thesis covers the following four parts:ChapterⅠ: Review. In this part, the new development of MOCPs, theintroduction of the room temperature ionic liquids and the method of ionothermalsyntheses have been briefly introduced.Chapter Ⅱ: Firstly, in this chapter the synthesis and structural characterizationsof two organic ligands, namely,4-imidazole benzoic acid （Hizbc） and （1,2,4-triazol-4-yl） benzoic acid （Htzbc）, is provided. Their nuclear magnetic resonance （NMR）, IR spectra and photoluminescent properties have been investigated.Interestingly, the Htzbc compound crystallized in a noncentrosymmetric space groupand displays a second harmonic generation （SHG） of2.5times of KDP （potassiumdihydrogen phosphate）. Then five metal-organic compounds were obtained based onthe Hizbc or Htzbc organic ligand under various ionothermal reactions. The crystalstructures, thermal stabilities and IR spectra of all compounds are presented.Compound [Zn₂Cl₂（izbc）4]_n（1） and Compound [Co₂Cl₂（izbc）4]_n（2） are isomorphous.They feature two-dimensional （2D） brick wall like network constructed fromdinuclear Zn₂（COO）₂units linked by izbc–ligands. Compound [Co（NO₃）₂（Htzbc）₂]_n（3） is a mononuclear structure. Compound [Cd（Htzbc）（NO₃）（C₂O₄）_0.5]_n（4）（C₂O₄isoxalic anion） has a2D layer where the cadmium ions are bridged by the oxalic anionsand nitrate anions. The hanging Htzbc ligands with the protonated carboxylic acidgroups are attached the two sides of the layer. Compound [Zn（tzbc）₂]_n（5） has anoncentrosymmetric3D diamondoid network framework. The Zn（Ⅱ） centers arebridged by the tzbc–ligands in a bidentate bridging fashion through the monondentatecarboxylate and triazole groups, to give a five-folded interpenetrated diamondoidnetwork. The noncentrosymmetric diamondoid structure of5exhibits a secondharmonic generation comparable to that of KDP.Chapter Ⅲ: Four new MOCPs based on aromatic carboxylic acid ligands weresuccessfully synthesized under ionothermal reactions. The general characterizationssuch as single-crystal X-ray diffraction and IR spectra were performed on thesemetal-organic compounds. Compound {（EMIM）₂[Zn₇（μ4-O）₂（1,4-NDC）6]}n（6）（EMIM and1,4-NDC₂–are1-ethyl-3-methylimidazolium cation and1,4-naphthalenedicarboxylate, respectively） with a426nm luminescent emissioncontains an uncommon heptanuclear [Zn₇（μ4-O）（μ2-COO）10] secondary building unit（SBU）. Each [Zn₇（μ4-O）（μ2-COO）10] SBU is bridged by twelve surrounding1,4-NDC₂–ligands to generate a3D framework structure with （42464） topology basedon an eight-connected node. The1-ethyl-3-methylimidazolium cation [EMIM]⁺of theIL acting as extraframework charge-balancing species is incorporated into the finalstructure. Compound [（EMIM）Gd（1,4-NDC）（NO₃）（C₂O₄）_0.5]_n（7）（C₂O₄is oxalicanion） is a three-dimensional （3D） framework where the oxalic anion is derived fromthe in situ reaction. The complex structure can be described as from thetwo-dimensional network that constructed by1,4-NDC₂–ligands and gadolinium ions,which is further linked by the oxalic anions to form the final3D structure. The cation[EMIM]⁺of the IL acts as extraframework charge-balancing species is incorporated into the1D channel. Compound [（EMIM）NaCu(1,4-NDC2]n（8）has an anionic3DNaCu（NDC）₂]_n^n-framework with charge-balancing species of [EMIM]⁺cationoccupying the channels of the3D framework. The carboxylate groups bridge copper（Ⅰ）and sodium（Ⅰ） ions into an infinite right-handed helical chain running along the c-axis.Each helical chain serves as a secondary building unit and is further linked to its fouradjacent neighbors with the same handedness in two orthogonal directions throughnaphthalene links generate a homochiral3D [NaCu（NDC）₂]_n^n-anionic framework.Compound [（EEIM）NaCu（BDC）₂]_n（9） has an3D [NaCu（BDC）₂]_n^n-anionicframework charge-balanced by the [EEIM]⁺cations （[EEIM]⁺is1,3-diethylimidazolium cation）. In the NaCu（BDC）₂]_n^n-anionic framework thecopper（Ⅰ） and sodium（Ⅰ） ions linked by the carboxylate groups to form a infinite（–Na–O–Cu–O–）_∞rod shaped secondary building unit （SBU）. Each rod-shapedheterometal-carboxylate SBU is linked by its four adjacent neighbors in twoorthogonal directions through the–C6H4–links generate a3D NaCu（NBC）₂]_n^n-anionic framework. The imidazolium cation [EEIM]⁺acts as extraframeworkcharge-balancing species for the anionic [NaCu（BDC）₂]_n^n-framework, and occupiesthe1D open channel.Chapter IV: A brief conclusion and an outlook on the article are presented in thelast chapter.