Syntheses, Photochemical Reactions And Physical Properties Of Functional Coordination Polymers

In recent years, the design and construction of coordination polymers by assembly reactions of metal ions with multitopic ligands have attracted considerable attention. This is due to their intriguing structural topologies and their potentials for use as functional materials in fluorescence, catalysis, adsorption, nonlinear optics and magnetism. It is noted that much attention has been paid to the coordination polymers that are assembled by polycarboxylic acids and multipyridyl ligands. The spacer of these multipyridyl ligands sometimes plays a critical role on the final structure. However, studies engaged in the assembly system containing polycarboxylates and multipyridyl ligands with a longer spacer are less reported. We are interested in the construction and chemical and physical properties of coordination polymers derived from polycarboxylates and multitopic N-containing ligands. In this thesis, we chose the longer dipyridyl ligands 1,2-bis（4-pyridyl）ethylene （bpe） and 1,4-bis[2-（4-pyridyl）ethenyl]benzene （1,4-bpeb） to react with polycarboxylates and metal ions. Finally, a series of coordination polymers were obtained. Based on the structural characters of the corresponding complexes, we investigated their photochemical reactions, photoluminescence properties, adsorption and separation properties. These results were briefly described as follows:1. The reaction between metal salts, bpe and carboxylic acids gave rise to six coordination polymers: [Zn（1,4-BDC）（bpe）]_n （1）, [Zn4O（1,3-BDC）₃（bpe）]_n （2）, {[Ag2（bpe）₂]（1,4-BDC）·（1,4-H₂BDC）}_n （3）, [Cd（bpe）（CBA）₂]_n （5）, [Cd（bpe）（BBA）₂]_n （7） and [Cd（bpe）（IBA）₂]_n （9）. Among them, 5 and 7 could undergo photodimerization reactions through single-crystal-to-single-crystal （SCSC） transformations, which afford [Cd（rctt-tpcb）0.5（CBA）₂]_n （6） and [Cd（rctt-tpcb）0.5（BBA）₂]_n （8）, respectively. 3 and 9 are also photoreactive, their photochemical products could be employed as precursor to synthesize high-dimensional coordination polymers {[Ag4（4,4′-tpcb）₃][（NO3）₄（H₂O）₆]}_n （4） and {[Cd（rtct-tpcb）Cl2]·2H₂O}_n （10）, respectively.2. Hydrothermal reactions between metal salts, 1,4-bpeb and polycarboxylic acids afforded thirteen complexes: {[Zn4（μ3-OH）₂（5-SIPA）₂（1,4-bpeb）₂]·4H₂O}_n （11）, [Cd2（1,3-PDA）₂（1,4-bpeb）₂]_n （13）, {[Zn6（μ-OH₂）（1,3-BDC）₆（1,4-bpeb）₄]·MeCN}_n （15）, {[Zn8（1,3-BDC）₈（1,4-bpeb）₄]·2H₂O}_n （16）, [Zn（μ-OH₂）（5-HO-1,3-BDC）（1,4-bpeb）]_n （17）, [Zn（1,3,5-HBTC）（1,4-bpeb）]_n （18）, {[Zn（5-NO2-1,3-BDC）（1,4-bpeb）]·2（H₂O）0.5}_n （19）, [Zn（5-Me-1,3-BDC）（1,4-bpeb）]_n （20）, {[Zn（1,4-PDA）（1,4-bpeb）]·2H₂O}_n （21）, [Zn（1,3-PDA）（1,4-bpeb）]_n （22）, [Zn4（μ-OH）₂（1,2-PDA）₃（1,4-bpeb）₂]_n （23）, {[Zn2（1,4-BDC）₂（1,4-bpeb）₂]·G}_n （24） and {[Zn4（1,4-BDC）₄（1,4-bpeb）₂]·G}_n （25） （24, G = 0.5MeCN·H₂O; 25, G = MeCN·2H₂O）.All these complexes exhibit good photoluminescence properties. Among them, 11 and 13 could undergo SCSC photochemical [2+2] cycloaddition reactions and afforded {[Zn4（μ3-OH）₂（5-SIPA）₂（bpbpvpcb）]·2H₂O}_n （12） and [Cd2（1,3-PDA）₂（tppcp）]_n （14）.3. The photochemical product 4,4′-tpcb was employed to construct a stable coordination polymer {[Ni2（μ2-OH₂）（1,3-BDC）₂（4,4′-tpcb）]·12H₂O}_n （26）. The fully desolvated crystals [Ni2（μ2-OH₂）（1,3-BDC）₂（4,4′-tpcb）]_n （27） that could be obtained by heating the crystals of 26. 27 is a reusable porous coordination network which could be used to separate the naphthalene/anthracene mixture. Furthermore, it could absorb many types of guest molecules. In these processes, 27 transformed to the following products: {[Ni2（μ2-OH₂）（1,3-BDC）₂（4,4′-tpcb）]·2C₁₀H₈}_n （28） {[Ni2（μ2-OH₂）（1,3-BDC）₂（4,4′-tpcb）]·3.5EtOH}_n （29） {[Ni2（μ2-OH₂）（1,3-BDC）₂（4,4′-tpcb）]·4C₆H₆}_n （30） {[Ni2（μ2-OH₂）（1,3-BDC）₂（4,4′-tpcb）]·FeCp2}_n （31） {[Ni2（μ2-OH₂）（1,3-BDC）₂（4,4′-tpcb）]·2C₆H₅OH}_n （32） {[Ni2（μ2-OH₂）（1,3-BDC）₂（4,4′-tpcb）]·2C₈H₈}_n （33）If 5-HO-1,3-H₂BDC, 5-NO2-1,3-H₂BDC or H3BTC were used to replace the 1,3-H₂BDC ligand, other three coordination polymers [Ni2（μ2-OH₂）（5-HO-1,3-BDC）₂（4,4′-tpcb）]_n （34）, [Ni2（μ2-OH₂）（5-NO2-1,3-BDC）₂（4,4′-tpcb）]_n （35） and {[Ni2（μ2-OH₂）（HBTC）₂（4,4′-tpcb）]·6H₂O}_n （36） would be produced.