Design, Synthesis, Structure And Properties Of Aromatic Polycarboxylic Acid Functional Complexes

The research about the metal-organic coordination polymers has attracted more and more attention under the direction of the crystal engineering. The design, synthesis, and exploration of the properties of coordination polymers (CPs) have gained momentum given their fascinating network topologies and various functional properties such as luminescence, magnetic and semiconductivity, gas sorption, and molecular recognition.In order to further investigate the influence of ligand on the structure of CPs for their rational design and synthesis, three semi-rigid aromatic multi-carboxylic acids ligands were selected to fabricate 16 new coordination complexes,{[Mn2(L1)4/3(H2O)3]·2H2O}n (1), Co(H2L1)2·(H2O)4 (2), Ni(H2L1)2·(H2O)4 (3), Zn(H2L1)2·(H2O)4 (4),{[Cu(HL1)·(H2O)]H2O}n (5), [Ni3(L1)2(bpy)2·(H2O)12]·4H2O (6), [Co3(L1)2(bPy)2·(H2O)12]·4H2O (7), Ni(HL1)(Py)(H2O)4 (8), [Cu2(L2)(μ4-OH)]n (9),{[Mn(L2)]H2O}n (10), {[Co2(L2)(μ3-OH)·H2O]n (11),{[Cd(HL2)]H2O}n (12),{[Zn3(L2)2(Py)6]·2H2O}n (13), [Ni3(bpy)2(SO4)3·(H2O)11]n (14),{[Cu2(L3)(μ2-OH)]·2H2O}n (15) and [Co3(L3)2·H2O)4]n (16) (H3L1= 1,3-bis(4-carboxylphenoxy) benzoic acid, H3L2= 1,3-bis(4-carboxylphenyl)oxy) benzoic acid, H3L3= 1,3-bis(3-carboxylphenyl)oxy) benzoic acid, bpy= 4,4’-bipyridine and Py= pyridine). We used the measurements in this thesis involve the single-crystal X-ray diffraction, the X-ray power diffraction, the IR measurement, to characterized the structure of the compounds and the thermo-gravimetric analysis, the magnetism and fluorescent analysis etc. to characteristic properties of the compounds. The thesis includes five chapters.1. Five new complexes, namely,{[Mn2(L1)4/3(H2O)3]·2H2O}n (1), Co(H2L1)2·(H2O)4 (2); Ni(H2L1)2·(H2O)4 (3), Zn(H2L1)2·(H2O)4 (4) and {[Cu(HL1)·(H2O)]·H2O}n (5) have been synthesized by the H3L1 and different transition metal ions. Complex 1 is a 3D framework, complexes 2-4 are discrete 0D structures. There are abundant intermolecular H-bonds in their packing structure. The unit were connected as three dimension structure by the intermolecular H-bonds. Complex 5 is 2D structure. Also, the thermal stabilities were discussed for five complexes. At the same time, the luminescent properties of 4 and magnetic properties of 1 and 5 were tested and discussed, respectively. We explored the relationships between structures and properties for the sets of compounds.2. Three new compounds, namely, [Ni3(Li)2(bpy)2·(H2O)12]·4H2O (6), [Co3(L1)2(bpy)2·(H2O)12]·4H2O (7) and Ni(HL1)(Py)·(H2O)4 (8) were synthesized under solvothermal conditions by employing a semi-rigid aromatic multi-carboxylic acid ligand (H3L1) and ancillary nitrogen ligand (bpy= 4,4’-bipyridine and Py= pyridine). The X-raydiffraction studies revealed that complexes 6-8 possessed zero-dimensional (OD) structures which were further extended to distinct 3D supramolecular nets by extensive hydrogen-bond interactions. The influence of the ancillary ligand has been discussed.3. In this study, six new coordination compounds, namely, [Cu2(L2)(μ4-OH)]n (9), {[Mn(L2)]H2O}n (10),{[Co2(L2)(μ3-OH)H2O]n (11),{[Cd(HL2)]H2O}n (12), {[Zn3(L2)2(Py)6]·2H2O}n (13), and [Ni3(bpy)2(SO4)3·11H2O]n (14) were synthesized using a semirigid aromatic multicarboxylate acid (H3L2) under solvothermal conditions, compounds 9-12 exhibited intriguing coordination features with 3D porous frameworks. Compound 12 is 2D porous frameworks. Compound 14 is 1D chain. In compound 10, Mn2+ state was readily oxidized to Mn3+ state. Both the compounds 9-12 contain one-dimensional (1D) chains extended via a (L2)3-bridge to generate 2D porous layers which are further connected by (L2)3-ligands to form 3D porous frameworks. Moreover, the magnetic properties of 9-11, luminescent properties of 12 and 13 were tested and discussed, respectively. The structural differences indicate that different coordination modes of the ligand play an important role in the self-assembly processes to form complexes with different structures.4. In this study, two new metal-organic frameworks (MOFs), namely, {[Cu2(L3)(μ2-OH)]·2H2O}n (15) and [Co3(L3)2·(H2O)4]n (16), were synthesized using a semirigid aromatic multicarboxylate acid (H3L3) under solvothermal conditions. Both the compounds 15 and 16 contain one-dimensional (ID) chains extended via a (L3)3-bridge to generate 2D porous layers which are further connected by (L3)3- ligands to form 3D porous frameworks. We research about the synthesis, structure, the thermal stability and magnetic properties. Moreover, magnetic susceptibility measurements demonstrated that compounds 15 and 16 exhibit antiferromagnetic coupling.5. We have discussed the relationship between the structures and the magnetic properties of the compounds which were constructed by three different aromatic multicarboxylic ligands with copper(Ⅱ), magnetic(Ⅱ) and cobalt(Ⅱ). Furthermore, the relationship between the structures and the fluorescence properties of the compounds of constructed by three different aromatic multicarboxylic ligands with zinc(II) and cadmium(II) were discussed, also. The results indicates that the degree of deprotonation and the conformation of the ligands can influence the structure of the compounds.