Construction Of Copper-Based Metal-Organic Frameworks And Their Small Molecule Adsorption Properties

Recently,rational design and synthesis of metal-organic frameworks(MOFs)as functional materials have attracted great attention due to their structural novelties and potential applications,such as gas adsorption and separation,catalysis,luminescence,electricity and drug delivery.The applications of MOFs materials and its inherent skeleton structure are closely connected.The copper halide-based compounds play an important role due to their abundant aggregate types in inorganic chemistry.So far,researches of the copper halide-based compounds were mainly focused on its potential applications of luminescence by using organic ligand coordination effect.In this thesis,twelve novel MOFs have been successfully synthesized.Furthermore,the structures and properties of these compounds have been investigated.The main results in the thesis are summarized as follows:(1)A novel homochiral zeolite-like metal-organic framework(ZMOF),[(Cu4I4)(C6H12N2)2]·[Cu2(bbimb)]·3DMF(compound 1),has been successfully constructed.The[(Cu4I4)(C6H12N2)2]n framework,having a zeolite-like topology,hosts DNA-like[Cu2(bbimb)]n polymers with double-helicity.The host-guest chirality interplay permitted the induced formation of an unusual gyroid MOF with homochirality and helical channels in the framework.Importantly,the enantiomeric pairs(compound 1M,1P)can be promoted and isolated in the presence of appropriate chiral inducing agents,affording enantioselective separation of chiral molecules as well as small gas molecules.(2)Five novel Cu-MOFs,(Cu4I4)[Cu2(pdc)2DMF2]2·2DMF·H2O(compound 2),(Cu4I4)[Cu3(cpna)3(Dabco)0.5DMF3]·4DMF· 4H2O(compound 3),(Cu4I4)[Cu3(cpna)3(H2O)0.5DMF3]· 4DMF· 4H2O(compound 4),[(Cu4I4)O][Cu4(pdc)4(Dabco)(H2O)2]3·xG(compound 5)and(Cu4I4)[Cu(pyip)(H2O)0.5]3·xG(compound 6),have been synthesized from pyridine-3,5-dicarboxylic acid(H2pdc),5-(4’-carboxylphenyl)nicotinic acid(H2cpna)and 5-(pyridine-4-yl)-isophthalic acid(H2pyip)with copper iodide under solvothermal conditions.Compound 2 features a(3,4,4)-c sqc5588 net,while compounds 3 and 4 are isostructural and possess new(3,4,4)-c topology.All of these compounds are composed of the binodal inorganic Cu2(CO2)4 paddle wheel and Cu4I4 cluster secondary building units(SBUs).It is worthy to note that the linkage between two nearby Cu4I4 clusters in compound 3 is μ2-Dabco,which changed to μ2-water molecule in compound 4.Furthermore,Compound 2 exhibits high CO2 adsorption behaviours as well as I2 uptake and release feature.By using the supermolecular building blocks(SBBs)strategy,compounds 5 and 6 have been synthesized.There are three types of cages in the framework with different shape and size.The N2,CO2,CH4,C2H6 and C3H8 gas adsorption of compound 5 have been investigated.The selectivity of adsorption of compound 5 for CH4 have been calculated by IAST calculating.Additionally,compounds 5 and 6 display the ability of uptake and release of the iodine.(3)Two fof type porous MOFs,[Cu2(bdfdpa)(H2O)2]·8DMF·2H2O(compound 7)and[Cu2(btadpa)(H2O)2]·7DMF·8H2O(compound 8),have been successfully synthesized by using different expanded tetracarboxylates ligands.Both of them exhibit good permanent porosity and high surface areas of 2205 and 1791m2 g-1,respectively.There are two kinds of distinct cages alternatively packed with a ratio of 1:1 in their framework.The spherical-like cages are composed of six Cu2(CO2)4 SBUs and twelve ligands.The shuttle-like cages are composed of six ligands and twelve Cu2(CO2)4 units,while the cage can also be regarded as face-decorated by the ligands.Due to open metal sites,different functional groups and suitable pore spaces,the two porous MOFs exhibit high adsorption performance for small molecule gases(CO2,CH4,C2H6 and C3H8)and removal of refractory organosulfur compounds.MOFs based on metal-organic polyhedra(MOP)might provide very efficient way for the construction of porous MOFs,because MOP themselves contain cavities,and the pore properties of the MOFs could be modulated at the level of the MOP.Compounds 9-12 features three types of cages with different sizes and shapes:a truncated tetrahedron(T-Td)configuration,a medium cage with cuboctahedron(cuo)geometry,and a large cage outlined in a truncated octahedron(T-Oh).