本論文研究首要設計為pyridine-2,5-dicarboxylate acid N-oxide (H2-2,5-pdco)與具吡啶基(pyridyl)之有機配子搭配,再與過渡金屬離子於水或醇類等溶劑中進行自組裝反應,形成金屬-有機配位聚合物16。首先合成不同性質之有機配子:4,4'-bipyridine (bipy)、trans-1,2-di(4-pyridyl)ethylene、2,2'-dipyridine (dipy)、2,2'-bipyrimidine (2bpm)等均具吡啶基(pyridyl)的配基。化合物{[Cu2(pdco)2(bipy)(H2O)2]•8H2O}n (1) 與{[Cu2(pdco)2(dpe)(H2O)2]•8H2O}n (2)藉由搭配不同長度的吡啶配基(bipy, bpe),因為π–π作用力的不同,化合物1形成了三次互穿的二維結構,而化合物2則是二維的鋸齒狀堆疊結構。化合物[Cu(pdco)(dipy)(H2O)]n (3) 與 [Cu2(pdco)2(2bpm)(H2O)]n (4)中因加入單邊螯合的吡啶配基(dipy)與雙邊螯合的吡啶配基(2bpm),而各產生一個零維的單體結構與二維的聚合物。化合物[Co(pdco)(H2O)2]n (5) 與[Zn(pdco)(H2O)2]n (6)為等結構(isostructure),其中藉由piperazine在反應過程中,扮演調控酸鹼值的角色,使得晶體的品質有顯著的提升。本研究也探討了N-Oxide (H2-2,5-pdco)有機分子與配位聚合物的吸收與放光特性。
Six N-oxide-based metal-organic frameworks were synthesized and their structures were characteized by single-crystal X-ray diffraction analysis. Compound {[Cu2(pdco)2(bipy)(H2O)2]•8H2O}n (1) and {[Cu2(pdco)2(dpe)(H2O)2]•8H2O}n (2) both use Cu2+ ion to display same coordination mode. However, compounds 1 and 2 show different crystal structures and packing patterns because the lengths of bipy and dpe ligands are variant. Compounds [Cu(pdco)(dipy)(H2O)]n (3) and [Cu2(pdco)2(2bpm)(H2O)]n (4) contain unilateral chelating dipy ligand and bilateral chelating 2bpm ligand, respectively. Therefore, 3 is a discrete monomer molecule and 4 forms a 2D coordination polymer. Compound [Co(pdco)(H2O)2]n (5) and [Zn(pdco)(H2O)2]n (6) are isostructures and display 1D chain structures. For compound 5, piperazine functions as a buffer, which results in a significantly better quality of the crystal. TGA data for 1-6 show that the structures could stabilize to 220 °C. The UV-Vis adsorption and luminescent properties of the compounds were investigated.