Synthesis, Properties And Properties Of Coordination Polymers Containing Rigid Triphenyl Tetracarboxylic Acid As Fluorescence Probes

As a most popular research topic in chemistry, materials and so on, the investigation of metal-organic coordination polymer has changed to the diversification of functionality from the structural diversity. Chemists have devoted to develop practical coordination polymers and a series of polymers working as adsorbing materials, magnetic materials, conductive materials, catalytic materials, medical materials and luminescent materials have been synthesized. How to obtain practical coordination polymers with high performance will be a focus work in this field.In the dissertation, the rigid ligand 1,1’,2’,1"-terphenyl-4,4’,4",5’-tetracarboxylic acid (H4tac) has been selected as the organic linkage, and 15 coordination polymers displaying the properties of magnetism or luminescence have been synthesesd by hydrothemal method or layer diffusion method, together with transation metal ion Co2+、Mn2+ and Cd2+. In the first part, the coordination modes of the ligand H4tac and the advantage and disadvantage in constructing magnetic coordination polymers have been discussed; the latter part of the dissertation has been devoted to the investigation of H4ttac constructing luminescent coordination polymers and the theories and applications of luminescent coordination polymers working as luminescent probes. In the dissertation, the following aspects have been primarily discussed:(1) The triphenyl tetracarboxylic acid H4ttac and the first transition metal ions of C2+ and Mn2+have been chosen respectively to construct coordination polymers with/without the regulation of various N-donor ligands, and four Co-based coordination polymers {[Co2(H2ttac)2(H2O)5]·(H2O)10}n (1)、[Co2(ttac)(pyridine)(H2O)3]n (2)、 {[Co2(ttac)(4,4’-bipy)1.5(H2O)]·(H2O)}n (3)、{[Co3(ttac)2(bpe)3(H2O)2]·(H2O)6}n (4) and five Mn-based coordination polymers{Mn3(Httac)2(H2O)g(H2O)2}n (5) {[Mn4.5(ttac)2(OH)(NMP)2(H2O)2](H2O)2}n (6)、{[Mn3(Httac)2(4,4’-bipy)(H2O)14]·(H2O)2}n (7)、{[Mn2(ttac)(4,4’-bipy)0.5(H20)3]·(H20)}n (8)和{[Mn2(ttac) (bpa)1.5 (H2O)5](H2O)3}n (9) have been synthesed. Polymers 1-9 display various structure characteristics and properties. The coordination modes of ligand H4ttac have been discussed, and the magnetism properties are also analysesd, where most of the coordination polymers display antiferromagnetism. Structure and property reasearches show that it is common for ligand H4tac to construct multinuclear metal clusters in coordination polymers for its four carboxylic groups, but there is no special advantage in the synthesis of functional magnetic coordination polymers for the large steric hindrance of H4ttac, which obstructs the linkage of the metal clusters.(2) The triphenyl tetracarboxylic acid H4ttac and Cd2+ ion with d10 configarition have been used to construct six coordination polymers:[Cd4(ttac)2(H2O)4]n (10),{[Cd(ttac)(bpe) (H20)2]·[(H4ttac)(bpe)0.5(H20)5]}n (11),{[Cd2(ttac)(bpe)(H2O)2]·(H2O)3}n (12), [Cd(H2ttac)bpp]n (13),{[Cd3(Httac)2(H2O)8]·(H2O)2}n (14) and {[Cd2(ttac)(H2O)6]·(H2O)6}n (15). Luminescence experiments show that H4ttac and coordination polymers 10-15 all display excellent luminescence properties. The luminescence emissions of 10-15 should all origin from the ligand.(3) Polymer 13 possesses a rare L1D+RID→3D dense stacking structure constructed by the vertical interpenetration of left-handed helices and right-handed helices through the flexible ligand bpp. Polymer 13 displays highly thermal stability, chemical stability, luminescence emission, and can respond to nitro aromatic compounds, Cu2+ and bases through the decrease of luminescence intensity and the move of spectra; especially for nitro aromatic compounds and Cu2+, the detection limits can reach 200 ppm and 40 ppm, respectively; the mechanisms are investigated. It is noteworthy that the polymer 13 possesses a dense structure without solvent accessible volume. As a result, this work enriches the selection of luminescent probes and provides a new approach to develop LCPs serving as luminescent sensor with high stability and less structure limits.(4) Two Homologous Coordination Polymers 14 and 15 both can function as the luminescecnt probes of Cu2+ through luminescence quenching, in which the mechanism is determined as photo-induced electron transfer. In this work, quantitative evaluations of the dynamic quenching and static quenching involved in the quenching processes of polymers 14 and 15 are performed. Importantly, the two polymers show distinct behaviors that static quenching dominates the quenching process of polymer 14, while polymer 15 shows much higher dynamic quenching effective. Further exploration shows that electron-rich active sites can promote the dynamic quenching process, and the high porosity helps enhance the dynamic quenching. These work and findings may bring new inspiration and ideas for chemists to develop coordination polymers probes with special functions.