Coordination Polymers Based On A Novel Flexible Tetrakis(imidazole) Ligand: Syntheses, Structures And Properties

In the first chapter, the concepts, the synthetic methods, the bonds or interactions of coordination polymers, the impact factors of the structures, and the possible applications are concisely introduced. Besides, the importance of the search project and summarized the important results obtained in the thesis are also presented.In the second chapter, thirteen Cd（II）-containing coordination polymers based on the novel tetradentate ligand tetrakis（imidazol-1-ylmethyl）methane （L）, namely, [Cd₂（L）₂（SO₄）₂（H₂O）₂]·4H₂O （1）, [Cd（L）（H₂O）₂]（NO₃）₂ （2）, [Cd（L）（Br）₂]·H₂O （3）, [Cd（L）0.5（fum）] （4）, [Cd5（adi）5（H₂O）₂]·6H₂O （5）, [Cd（1,3-bdc）（L）0.5] （6）, [Cd（1,4-bdc）（L）0.5（H₂O）]·H₂O （7）, [Cd₂（5-OH-1,3-bdc）₂（L）]·2H₂O （8）, [Cd3（1,3,5-btc）₂（L）]·4H₂O （9）, Cd3（1,2,3-btc）₂（L）（H₂O）₂]·2.5H₂O （10）, [Cd（1,2,4-Hbtc）（L）]·0.75H₂O （11）, [Cd7（btca）3（μ3-OH）₂（L）₂]·8H₂O （12）, [Cd₂（odpa）（L）（H₂O）₂]·H₂O （13）, where H₂fum = fumaric acid, H₂adi = adipic acid, 1,3-H₂bdc = 1,3-benzenedicarboxylic acid, 1,4-H₂bdc = 1,4-benzenedicarboxylic acid, 5-OH-1,3-H₂bdc = 5-OH-1,3-benzenedicarboxylic acid, 1,3,5-H3btc = 1,3,5-benzenetricarboxylic acid, 1,2,3-H3btc = 1,2,3-benzenetricarboxylic acid, 1,2,4-H3btc = 1,2,4-benzenetricarboxylic acid, H4btca = 1,2,4,5-benzenetetracarboxylic acid, and H4odpa = 4,4’-oxydiphthalic acid, have been synthesized under hydrothermal conditions. Compound L·5H₂O shows a novel 3D （3,8）-connected supramolecular architecture with a unique （3·52）₂（34·42·56·612·73·8） topology. Compounds 1–3 were isolated by the reactions of L with inorganic anions （SO₄2-, NO₃-, Br-）. Compound 1 displays a 4-connected PtS network. Compound 2 exhibits a 3D 4-connected zeolite ABW net, while compound 3 is a 2D （44）-sql net. 4 exhibits a 2-fold interpenetratingα-Po net, while 5 shows a non-interpenetrating 3D framework. 6 shows a 3D （65·8） CdSO₄-type framework, whereas compound 7 has a different 3D framework with （4·62·72·8）（42·62·7·8） topology. 8 shows a 2D layer structure, which is further extended into a 3D supramolecular framework by the hydrogen bonds. In 9, the Cd（II） atoms are bridged by L and 1,3,5-btc ligands to form a 3D structure. In 10, the trinuclear Cd（II） clusters are linked by the L and 1,2,3-btc ligands to generate a chiral 3Dα-Po structure. In 11, the Cd（II） centers are connected by the L ligands and the partially deprotonated 1,2,4-Hbtc ligand to yield a 2D layer structure. In compound 12, the btca ligands link the Cd（II） centers to form a 3D Cd-btca framework, and the L ligands further stabilize the 3D structure. In compound 13, odpa ligands coordinate to the Cd（II） atoms to generate a 2D layer, which is further linked by L ligands to form a 3D framework. The structural differences of compounds 1–13 indicate that the presence of the different anions play an important role in the resulting structures of the coordination polymers. The infrared spectra and luminescent properties were also investigated for the compounds.In the third chapter, eight new metal-organic frameworks based on the tetrakis（imidazole） ligand tetrakis（imidazol-1-ylmethyl）methane （L）, [Zn2（L）（SO₄）₂]·2H₂O （14）, [Co（L）（SO₄）]·1.25H₂O （15）, [Zn2（L）（1,2-bdc）₂]·3.5H₂O （16）, [Co2（L）（1,2-bdc）₂]·2.5H₂O （17）, [Zn2（L）（1,3,5-btc）（1,3,5-H₂btc）₂]·5H₂O （18）, [Co1.5（L）（1,3,5-btc）] （19）, [Zn2（L）（btca）]·4H₂O （20）, [Co（L）（H₂O）₂]·（H₂btca）·1.5H₂O （21）, where 1,2-H₂bdc = 1,2-benzenedicarboxylic acid, have been synthesized under hydrothermal conditions. Compound 14 displays a two-fold interpenetrated PtS net. Compound 15 possesses a binodal （4,6）-connected topology with Schl·fli symbol of （3·4·53·6）（32·4·54·67·7）. Compound 16 shows a trinodal （3,4）-connected topology with the Schl·fli notation of （66）（65·8）（63）. Compound 17 is isostructural with 16. The compound 18 is a binodal （3,4）-connected 2D net with the Schl·fli notation of （62·8）（4·64·8）. 19 shows a trinodal （3,4）-connected framework with Schl·fli symbol of （4·82）₂（42·84）（84·122）. Compound 20 exhibits a pentanodal net with Schl·fli symbol of （4·6·84）（42·64）（42·84）（42·83·10）（4·62·83）. Compound 21 is a rare 4-connected 2D net with the Schl·fli symbol of （43·63）. The influence of the metal atoms and ligands on the structures of the coordination polymers has been discussed. The thermogravimetric analysis and luminescent properties were also investigated for the compounds.In the fourth chapter, five new silver（I） coordination polymers constructed from tetrakis（imidazol-1-ylmethyl）methane （L） and various anions have been synthesized, namely, [Ag（L）0.5]（NO₃）·0.5（H₂O） （22）, [Ag（L）0.25Br] （23）, [Ag2L]（mal）·6.25H₂O （24）, [Ag2L（1,3-bdc）]·4H₂O （25）, and [Ag2L（1,4-bdc）0.5]·0.5（1,4-bdc）·7.5H₂O （26）, where H₂mal = maleic acid. In compound 22, Ag（I） atoms are connected by the L ligands to form a 2D （44·62） network with free NO₃- anions filled in the channels. The resulting layers are extended into 3D supramolecular frameworks throughπ–πinteractions. In compound 23, the L ligands link the Ag4Br4 cluster to form a two-fold interpenetrating diamond architecture. In compound 24, the Ag（I） atoms are bridged by the L ligands to furnish a 3D trinodal （3,4）-connected （62·8）（4·6·8）（4·62·82·10） net with the mal ligands just as free couteranions. In compound 25, the 1,3-bdc ligand coordinates to the Ag（I） center in a monodentate mode. The L ligands link the Ag（I） atoms to form a 2D double layer structure with Schl·fli symbol of （62·8）₂（64·82）. In compound 26, the L and 1,4-bdc ligands connect the Ag（I） atoms to form a complicated 3D （3,4）-connected framework with Schl·fli symbol of （4·102）₂（42·6）₂（42·103·12）（42·6·103）₂. The influence of the anions on the structures of the coordination polymers has been discussed. Additionally, the luminescent properties of these compounds were also studied.The fifth chapter is the conclusions.