以幾何誘導錯合反應及選擇性去錯合反應合成金屬配體

Abstract

近幾十年來，以超分子化學為基礎的穩定結構已被大量合成問世，其中，聯三吡啶及其衍生物亦能透過配位驅動的自組裝過程來建構金屬超分子結構。為了建造複雜度更高的超分子化合物，我們設計一種新穎的合成方法來獲得合適的金屬配體。 藉由幾何結構的誘導效應與配體的配位選擇性，我們建造出在結構中心具有動力學穩定性的自組裝錯合物，此外，由於金屬與配體之間的配位鍵具易變性，因此可藉由配體與中間產物的可逆性來增加分子的自修復能力。基於設計好的配體與互補的配基對系統，我們可以獲得菱形與謝爾賓斯基三角形的金屬超分子結構。緊接著，利用選擇性去錯合反應，我們可以合成分別擁有一個及三個動力學穩定性的全同配位體鍵結的金屬配體。 在此研究中，我們可以利用新合成的金屬配體來建造出更複雜的立體結構，藉由互補的配基形狀與配體對，我們合成出含有三片菱形的螺旋槳分子以及具有四片謝爾賓斯基三角形的八面體籠狀分子。所有結構均透過以下方式進行鑑定：一維氫核磁共振光譜、二維相關氫譜、電噴灑游離質譜、行波離子遷移二維質譜、基質輔助雷射脫附電離飛行時間質譜、原子力顯微鏡以及穿透式電子顯微鏡等。

Over the past few decades, a large number of well-defined structures have been synthesized in a supramolecular manner. 2,2':6'2"-Terpyridine derivatives have been used to create metallo-supramolecular structures by coordination-driven self-assembly process. For the purpose of assembling architectures with higher complexity, we designed a novel method to synthesized metalloligands. Through the geometry-induced method and the selectivity of chelating ligands, we constructed self-assembly architectures with kinetically inert bonds in the core of planar structures. Moreover, the reversibility between components and intermediates would increase self-correcting ability due to the labile metal-ligand coordination bonds. The metallo-supramolecular rhombus and Sierpiński triangle can be prepared in quantitative yields based on the well-defined building blocks and complementary ligand pairing systems. Subsequently, metalloligands with respective one and three kinetically inert homoleptic connections were successfully generated after selective decomplexation reaction. Building on the newly-synthesized metalloligands, we created more complicated structures, a molecular propeller and an octahedral cage that involved four Sierpiński triangles, based on the complementary geometry and ligand pairing. The structure characterization was carefully established by NMR, ESI-MS, ESI-TWIM-MS, MALDI-TOF, AFM, and TEM experiments.