| Metal–organic frameworks(MOFs) have attracted considerable attentions owing to their high surface area, a variety of pore sizes, controllable structures and readily tailorable functions. As an important class of which has great potential in a wide range of applications, MOFs have a broad development and applications in many fields, such as gas adsorption and separation, optical materials, catalysis, magnetic materials and proton conduction. Because the MOFs contrasted by multicarboxylic acid ligands have many advantages, such as the valuable visualized and well-defined structure, it have been a hot point which many researchers are competing for have a inveset in. In this thesis, we are aiming to introducing the phosphonated group and sulfonated group into the multicarboxylic acid legands, and constructing novel proton-conducting MOFs with good promising future. These complexes were characterized by X-ray single crystal diffraction, Infrared spectroscopy(IR),Thermogravimetric analysis(TG), Podwer X-ray diffraction(PXRD), Elemental analysis and Inductive coupled plasma emission spectromete(ICP).This thesis is mainly including the following two parts:1. Six MOFs with unique structures were obtained by the hydrothermal method based on disodium-2,2’-disulfonate-4,4’-oxydibenzoic acid(Na2H2DSOA) 、4,8-disulfonyl-2,6-naphthalenedicarboxylic acid(H4L1) 、5-(phosphonomethyl)isophthalic acid(H4L2) 、 1,2-Di(4-pyridyl)ethane(bpe) 、4,4’-Bipyridine(4,4’-bpy) with Cd(NO3)2·4H2O, Co(NO3)2·6H2O, Cd(OAc)2·2H2O,Cu(NO3)2·3H2O, namely: {[Co(H2DSOA)2] ? NO3 ? 3Na ? CH3OH}n(1),{[Cd(H2DSOA)] ? 6CH3OH}n(2), {[Cd2(L1)(4,4’-bpy)2(H2O)4] ? H2O}n(3),{[Cd2.5(L1)(OH)(H2O)2]}n(4), {[Cu(L1)0.5(bpe)] ? H2O}n(5),{[Cu0.5(L2)0.5]?0.45(CH3CN)?2.6H2O}n(6). Compound 1 displays a 2D networks and adopts the AB stacking sequence, all the-OH groups from the legands are uncoordinated. Compound 2 also has the uncoordinated-OH, it has a 3D superrmolecules structure whish is consisted of the metal atoms and the legands.Compound 3 displays a 3D networks with the two-nuclear Cd second building units(SBUs), bpe and the ligands, all uncoordinated oxygen atoms from the sulfonated group are aiming to the pores. Compound 4 also displays a 3D network with the two-nuclear Cd SBUs and L14-, all uncoordinated oxygen atoms from the sulfonated group are aiming to the pores. Compound 5 also displays a 3D supermolecules structure which is composed of the Cu II atom, 4,4’-bpy and legands. Compound 6 has a 3D supermolecules structure which is composed of the Cu II atom and the legands, it has two kinds of cages which formed the hydrophilic and hydrophobic pores, we disscuss the proton conductivity of compound 6 because the ways between the uncoordinated-OH group of the phosphonated groups and the free water molecules could transfer the protons.2. A new 2D Ln-MOFs with novel structure was obtained from the hydrothermal method through the 5-(phosphonomethyl)isophthalatee(H2L2) ligand with the Ln(III), namely:[Eu(L2)·(Me2NH2)](Compound 7). Compound 7 is composed of the 2D negative layer and the free [(CH3)2NH2]+ cations, strong and continuous 1D hydrogen bonds are formed through acid-base pairs which are composed of the ordered [(CH3)2NH2]+ and the uncoordinated oxygen atom from the phosphonate group. Compound 7 exhibited high proton conductivity both in anhydrous conditions and hunid conditions which is rarely roported for PCMOFs.The crystals of compound 7 exhibited high proton conductivity of 1.24 × 10-3 S cm-1in anhydrous conditions(at 150 o C), which is among the highest proton conduction that operated at similar conductions. Compound 7 also gained high proton conductivity under humid and N,N-Dimethylformamide(DMF) conditions(over 10-3S cm-1). The crystals of compound 7 showed high proton conduction under anhydrous condition mainly owing to the efficient 1D hydrogen bonding which yield the effcient proton transfer pathway, while the vapor water and DMF molecules come to build the efficient proton pathway under humid and DMF conditions. Particularly,the compound 7 shows super hydrolytic and thermal stability, which provides the possibility to the future implementation in devices such as fuel cell membrane electrode assemblies. |
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