The Syntheses And Properties Of Mixed-Metal/Mixed-Ligand Metal-Organic Framework Materials

Metal-organic frameworks（MOFs）are a kind of novel crystalline materials,which are highly ordered porous materials formed by the connection of metal ions or clusters and organic ligands through the self-assembly process.Due to their structural particularity,they were widely explored in many fields.Therefore,increasing the diversity of MOFs have attracted the attention of many researchers.Among them,the introduction of multiple metal ions or ligands into one MOF is an effective way to obtain MOFs with high complexity and versatility.However,accurate control over the structures and performance of MOFs remains a challenging task.Therefore,it is a difficult task to prepare functionally adjustable mixed-metals or mixedligands MOFs.The contents of this thesis are described as follows:1.Two kinds of mixed-metals MOFs,namely MIL-125（Ti-Eu）and MIL-125（Ti-Tb）,were synthesized by the employment of europium nitrate or terbium chloride,1,4-terephthalic acid and titanium isopropyl alcohol as raw materials through solvothermal method.Both two materials were utilized to detect a series of metal ions at certain concentrations.The results suggested that the detection limits of MIL-125（Ti-Eu）for copper and iron ions are 3.60 and 5.05 μM,and the detection limits of MIL-125（Ti-Tb）for copper and iron ions are 5.79 and 3.54μM,respectively.2.A three-dimensional cobalt-based MOF,（NENU-1005,NENU=Northeast Normal University）was synthesized by the employment of 1,2,4-triazole（Htz）,4,4’,4"tricarboxytriphenylamine（H₃TCA）combined with Co2+ salt as precusors by solvothermal method.A three-dimensional zinc-based MOF（NENU-1006）was synthesized using adenine（Hade）,4,4’,4"-tricarboxytriphenylamine combined with Zn2+salt as precusors.{（Me₂NH₂）₃[Co_2.5（μ₂-OH）（tz）（TCA）₂（DMF）_0.5·Guest]}（NENU-1005）{（Me₂NH₂）[Zn₄（μ₂-O）（ade）（TC A）₂（H₂O）·Guest]}（NENU-1006）In these two structures,metal ions were linked by tz^-or ade^-fragments to form metallic chains,which were further extended to three-dimensional frameworks by the tridentate TCA^3- fragments.Both structures are rich in COO-groups and C=O can be combined with K⁺,which is expected to be used as anode materials for potassium ion batteries.Furthermore,the assynthesized MOF materials were mixed with single-walled carbon nanotubes（SWCNT）by solid phase ball milling method to prepare the corresponding carbon composites,NENU1005@SWCNT and NENU-1006@SWCNT.The introduction of SWCNT not only enhanced the electronic properties of the materials,but also improved the electrochemical performance of NENU-1005 and NENU-1006.This work provides a promising platform for the development of MOFs-based electrode materials.3.Five MOF structures（NENU-1007 to NENU-1011）were obtained by solvothermal method through the employment of 1,2,4-triazole or adenine,Co2+ salts and a variety of tri dentate ligands（2,4,6-tri（4-carboxyphenyl）-1,3,5-triazine（H₃TATB）,1,3,5-tri（4carboxyphenyl）benzene（H₃BTB）and 2,4,6-trimethyl-1,3,5-tri（4-carboxyphenyl）benzene（H₃Me-BTB））as precusors.{（Me₂NH₂）[Co₃（TATB）_4/3（BDC）（ade）]·2H₂O}（NENU-1007）{Co₃（μ-O）（T ATB）_4/3}（NENU-1008）{（Me₂NH₂）[Co₃（μ3-O）（BTB）5/3]}（NENU-1009）{（Me₂NH₂）10[Co6（tz）₂（BTB）8/3（μ₂-O）4（μ3-O）₂]}（NENU-1010）{Co₃（Me-BTB）₂（DMA）₂}（NENU-1011）The above five compounds were fully characterized.In addition,the iodine capture performance of NENU-1009 and NENU-1010 were studied.The results suggested that it is a reversible process for iodine absorption and release.