Design,Synthesis Of Heterometallic Metal Organic Frameworks And Explore The Potential Application Performance

Metal-organic frameworks?MOFs?as a class of crystalline porous material,attract more and more attention,because they possess various potential applications,such as in gas adsorption/separation,catalysis,chemical sensing,and ion exchange.Oriented design and synthesis of metal-organic frameworks with specific structures and functions has been a hot topic in the material chemistry.So far,a large number of metal organic frameworks have been successfully reported.However,some key problems in terms of reasonable design,optimization of synthesis methods and analysis of influencing factors are still need to be explored.Based on the principle of crystal engineering,this paper is dedicated to the design and synthesis of heterometallic metal organic frameworks?HMOFs?and exploration of the related properties.In addition,a series of problems namely raw material selection and synthesis method were also studied.Finally,we obtained several kinds of HMOFs and carried out structural analysis and performance characterization.The main achievements of this paper include the following aspects:1.Using the in situ ligand formation strategy,by carefully selecting the bifunctional ligand 6,6'-dithiobisonicotinic acid containing the easily cleavable S-S bond and the metal ion In³⁺ and Cu⁺,In the solvent thermal system through the S-S bond fracture bond in situ formation of multi-functional organic ligand,and successfully prepared a cationic skeleton of the three-dimensional heterometallic metal-organic framework {[?CH₃?₂NH₂]InCu₄L₄·x S}?BUT-52?.It has a very rare sulfur atom decorated dumbbell-shaped cage structure.Through a series of experiments show that this material has a good gas adsorption/separation performance.The main mixing components C₂H₂,C₂H₄ and C₂H₆ in natural gas CH₄ have good adsorption and separation ability,simultaneously;At the same time,based on the dumbbell-shaped structure with sulfur atom decorate in the BUT-52 structure,and the sulfur atom and the heavy metal ion Hg have a strong binding ability,BUT-52 has the ability to response Hg²⁺ from the extremely low concentration of methanol solution,And further adsorbed and removed Hg²⁺.At the same time because of the CUT-52 cation skeleton structure,so that It also has a good adsorption effect for the anion dye.2.Under solvent thermal conditions,we selected a nitrogen-rich organic ligand 2,6-bis [3-?pyrazin-2-yl?-1,2,4-triazole] pyridine?H₂L?,by controlling the reaction time temperature and PH value,etc.We obtained a one-dimensional chain-like coordination polymer [FeIIL?H₂O?]·2H₂O?complex 1?,Through the study we found that complex 1 has an extraordinary acid and alkali properties and thermal stability.And a novel heterogeneous [2×2] lattice complex [FeIII₂Na₂L₄?H₂O?₄]·8H₂O?complex 2?was successfully prepared by solvating the crystal of complex 1 as a template in a methanol solution saturated with sodium azide.This process achieves single crystal transformation from one-dimensional single-metal chains to [2×2] isomeric lattice structures.Complexes 1 and 2 have potential applications in terms of magnetic and electrochemical value and are worth exploring further.3.First of all,by the guidance of soft and hard acid-base theory,we reasonable choice selection of ligand and metal source,we succeed synthesized a two-dimensional layered single metal organic frameworks?compound 3?with a 6-connect rare earth cage secondary building unit and a three-dimensional single metal organic skeleton compound?compound 4?with a 12-connect rare earth cage secondary building unit.And we carried out structural analysis and a series of characterization.Subsequently,we re-metallized the skeletal structure of the three-dimensional single metal organic frameworks compound 4 with an open chelating site to obtain a hetero metal organic skeleton compound having an open metal site,and then we studied the effect of this HMOFs on the organic catalysis.We found that Pd²⁺ metallized compound 4 to dehydrogenation of substituted cyclohexenones to phenolsa has a certain catalytic effect.