Rotaxane formation by an allosteric pseudomacrocyclic anion receptor utilising kinetically labile copper(I) coordination properties
Rotaxane formation by an allosteric pseudomacrocyclic anion receptor utilising kinetically labile copper(I) coordination properties
复制标题
利用动力学不稳定的铜 (I) 配位特性，变构假大环阴离子受体形成轮烷
DOI：
10.1039/d2dt03331c
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Tatsuya
中科院分区：
文献类型：
--
作者：
AIZAWA;Taeko; AKINE;Shigehisa; SAIKI;Toshiyuki; NAKAMURA;Takashi; NABESHIMA;Tatsuya
轮烷类化合物是一类重要的环轴互锁分子，在分子机械、开关型催化剂等方面有着广泛的应用。构建以阴离子为靶点的互锁结构是一个重要的问题，正如阴离子基团通常在许多生物大分子中丰富的事实所证明的那样。我们现在报道了一种变构假大环阴离子受体作为一个环，其在具有阴离子站的轴的存在下以自动剪切的方式自发地产生轮烷，这不需要像通常的剪切那样的连续成环反应。我们设计了一个带有三个阴离子识别部分的线性配体1，即，1的中心有一个硫脲基，2个脲基靠近2，2 ′-联吡啶末端。1与Cu+的络合以分子内方式进行，定量地导致大环结构[1·Cu]+。与1相比，[1·Cu]+的阴离子结合能力显著更大（正变构效应），这是由于三个阴离子识别部分以环状方式和静电相互作用的大环化排列。此外，假大环单元的动力学不稳定但化学稳定的配位性质促进了在室温下自发形成具有磷酸根轴的轮烷。
Rotaxanes, which are composed of ring and axle components, are important interlocked molecules with wide applications such as molecular machines and switchable catalysts. The construction of interlocked structures targeting anions is an important issue, as evidenced by the fact that anionic groups are usually abundant in many biomacromolecules. We now report an allosteric pseudomacrocyclic anion receptor as a ring that spontaneously generates a rotaxane in an auto-clipping way, which does not require the successive ring forming reaction like usual clipping, in the presence of an axle with an anionic station. We designed a linear ligand 1 bearing three anion recognition moieties, i.e., one thiourea group at the centre and two urea groups near the 2,2′-bipyridine ends of 1. The complexation of 1 with Cu+ proceeded in an intramolecular manner that quantitatively led to a macrocyclic structure [1·Cu]+. Compared to 1, the anion binding ability of [1·Cu]+ was significantly larger (positive allosteric effect) due to the macrocyclization arrangement of the three anion recognition moieties in a cyclic fashion and electrostatic interaction. In addition, the kinetically labile but thermodynamically stable coordination properties of the pseudomacrocyclic ring unit promoted the spontaneous rotaxane formation with a phosphate axle at room temperature.