利用模板合成法建構環中環異金屬超分子及含吡啶鹽巨環分子

Abstract

近十幾年間有越來越多的超分子錯合物在文獻中出現,利用不同角度的配位基可 以建構許多不同結構的超分子錯合物,例如三角形、四邊形、六角形等平面結構或 是四面體、正方體、八面體等超分子錯合物,另一方面,透過模板法合成可以用來 合成以往難以得到的分子結構,因為三聯吡啶三角形具有極高的穩定性,本工作選 用三聯吡啶三角形為合成模板,而本工作的重點是利用模板合成法建構雙金屬超 分子以及環狀分子,在配位基的設計上,六十度的三聯吡啶配位基上外修飾吡啶, 首先將配位基 L1 , L2, L3 及 L4 加入鋅離子,二價鋅離子會與三聯吡啶配位形成 金屬超分子三角形,再引入二價鈀或鉑離子可以得到雙金屬超分子[Zn3Pd3L13]、 [Zn3Pd6L23]、[Zn3Pd6L33] 和[Zn3Pt12L43],除了逐步法以外,因為三聯吡啶具有較強 的配位能力,也能利用一鍋合成法得到雙金屬超分子。在合成共價键聯結的大環分 子上,吡啶鹽親核取代反應被選用來合成環狀分子,因為吡啶鹽親核取代反應可以 在溫合的環境下進行,而配位基 L1 先被選用來合成環狀分子,在反應結束後,利 用乙二胺四乙酸去掉金屬,順利合成分離出單聚體 L1M、二聚體 L1D 以及三聚體 1T 1M 1D 1T L ,各別回加金屬後取得[Zn3L 3]、[Zn4L 2] 和 [Zn3L ],也利用回加金屬實驗 順利求得反應結束時各個生成物的轉化率,與對照實驗比較,發現三角形模板能夠 提高三聚體的轉化率。

Over the last decade, more and more supramolecular complexes have been created. Through ligand design, different kinds of supramolecular structures could be synthesized. For example, triangular, square and hexameric supramolecular macrocycles could be easily prepared by adjusting binding angles. On the other hand, through the templated synthesis, sophisticated self-assemblies could be easily obtained. Because of the high stability of terpyridine-based triangles, the terpyridine-based triangle was chosen as the template. The presented research is mainly focused on using templated synthesis to prepare heterometallic complexes and covalently linked macrocycles. The ligands L1, L2, L3 and L4 containing a 60°-bent bisterpyridine in the center and pyridines at the ends were synthesized. When the ligands were mixed with ZnII ions, the terpyridine-based triangle templates were formed in solution. In the first part of this work, the triangular templates were utilized to produce heterometallic complexes. When the templates were further mixed with PdII or PtII ions, the heterometallic complexes [Zn3Pd3L13], [Zn3Pd6L23], [Zn3Pd6L33] and [Zn3Pt12L43] were obtained in quantitative yields. In addition to the stepwise procedure, the one-pot procedure to synthesize the heterometallic complexes was also achieved. In the second part of this work, the triangular template was utilized to produce covalently linked macrocycles. A SN2 reaction, pyridinium formation, was selected to form the outer macrocycles because the reaction could take place under mild conditions. Ligand L1 containing two pyridine units was used for this trial. After the cyclization and decomplexation reactions, macrocycles L1M, L1D and L1T were obtained. After re-complexation with ZnII ions, [Zn3L1M3], [Zn4L1D2], and [Zn3L1T] were obtained quantitatively. On the basis of the 1H NMR results, L1T was the major product. In contrast, the control experiment in the absence of the triangular template showed that the monomerLNM was the major product.