In this work, we employed for the first time a dinuclear bis[tris(2-aminoethyl)amine] cryptate to obtain the self-assembly of pseudorotaxane structures in an aqueous solution. The goal was achieved by exploiting the well-known affinity of the dicopper azacryptate with diphenyl spacers for the terephthalate anion. In particular, a series of molecular threads were synthesized by appending either alkyl or polyoxyethylene chains on both sides of the terephthalate benzene ring. The obtained dicarboxylic acids were precipitated as sodium salts, and their affinity toward the dicopper azacryptate was determined in a methanol/water mixture (pH 7). Experimental investigations showed that the chains’ length and nature have a small impact on the 1:1 binding constants, whose values range between 4.98 and 5.18 log units. Computational studies indicated that the molecular axle is threaded through the azacryptate cavity, with the terephthalate group wedged between the two copper ions, coordinating both of them in the apical position (the one that, in the free azacryptate, is occupied by a water molecule). Compared to the inclusion complex with the plain terephthalate anion, a slight strain was found in the pseudorotaxane structure, induced by the inner chain of the thread inside the cavity. These results may be of great interest in all of the fields of science and technology in which host–guest recognition and molecular cages are applied.

中文翻译：

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从Dicopper（II）分子笼和二羧酸酯轴的伪轮烷结构的自组装。

在这项工作中，我们第一次使用双核双[三（2-氨基乙基）胺]地穴酸盐来获得水溶液中拟轮烷结构的自组装。通过利用双铜氮杂双酚与二苯间隔基对对苯二甲酸阴离子的众所周知的亲和力来实现该目的。特别地，通过在对苯二甲酸酯苯环的两侧上附加烷基或聚氧乙烯链来合成一系列分子线。所获得的二羧酸以钠盐形式沉淀，并在甲醇/水混合物（pH 7）中测定其对双铜氮杂盐酸盐的亲和力。实验研究表明，链的长度和性质对1：1的结合常数影响很小，其常数范围在4.98和5.18对数单位之间。计算研究表明，分子轴穿过氮杂穴腔，对苯二甲酸酯基团被楔在两个铜离子之间，使它们的两个配位处于顶端位置（在自由的氮杂穴中被水分子占据的位置）。 。与具有普通对苯二酸酯阴离子的包合物相比，在假轮烷结构中发现了轻微的应变，这是由腔内螺纹的内链引起的。这些结果可能会在应用主客体识别和分子笼的所有科学技术领域中引起极大兴趣。被水分子占据）。与具有普通对苯二酸酯阴离子的包合物相比，在假轮烷结构中发现了轻微的应变，这是由腔内螺纹的内链引起的。这些结果可能会在应用主客体识别和分子笼的所有科学技术领域中引起极大兴趣。被水分子占据）。与具有普通对苯二酸酯阴离子的包合物相比，在假轮烷结构中发现了轻微的应变，这是由腔内螺纹的内链引起的。这些结果可能会在应用主客体识别和分子笼的所有科学技术领域中引起极大兴趣。