Mechanochemical Access to a Short-Lived Cyclic Dimer Pd2L2: An Elusive Kinetic Species to Molecular Triangle Pd3L3 and Molecular Square Pd4L4.
Mechanochemical Access to a Short-Lived Cyclic Dimer Pd2L2: An Elusive Kinetic Species to Molecular Triangle Pd3L3 and Molecular Square Pd4L4.
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机械化学获得短寿命环状二聚体 Pd2L2：分子三角形 Pd3L3 和分子方形 Pd4L4 的难以捉摸的动力学物种。
DOI：
10.1002/anie.202116980
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发表时间：
2022
影响因子：
--
通讯作者：
Kaking Yan
中科院分区：
文献类型：
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作者：
Yan Liu;Fang;Kaking Yan
基于Pd的分子正方形Pd 4L 4和三角形Pd 3L 3代表了近30年来在该领域蓬勃发展的金属配位多面体的分子祖先。顺式保护的Pd离子和2，2 '-联吡啶之间的常规溶液基反应仅得到Pd 4L 4和/或Pd 3L 3作为唯一产物。本文首次证明了在无溶剂机械化学条件下，自组装能量场可以被化学调控形成难以捉摸的环状二聚体Pd 2L 2。在不存在溶剂的情况下，Pd 2L 2在固态下是无限稳定的，但在溶液中迅速转化为其热力学产物Pd 3L 3和Pd 4L 4，证实Pd 2L 2在基于溶液的自组装过程中是短寿命的动力学物种。我们的研究结果强调了机械化学如何赠款人们获得与传统溶液条件截然不同的化学空间。这提供了一个独特的机会，以隔离难以捉摸的物种在自组装过程中，太反应，以“看到”和“捕获”。
Pd-based molecular square Pd4L4 and triangle Pd3L3 represent the molecular ancestors of metal-coordination polyhedral that blossoms the field the last 30 years. Conventional solution-based reactions between cis-protected Pd ions and 2,2'-bipyridine exclusively give Pd4L4 and/or Pd3L3 as the sole products. We herein showed that, under solvent-free mechanochemical condition, self-assembly energy landscape can be thermodynamically manipulated to form an elusive cyclic dimer Pd2L2 for the first time. In the absence of solvent, Pd2L2 is indefinitely stable in solid-state, but converts rapidly to its thermodynamic products Pd3L3 and Pd4L4 in solution, confirming Pd2L2 as a short-lived kinetic species in the solution-based self-assembly process. Our result highlights how mechanochemistry grants access to vastly different chemical space than in conventional solution conditions. This provides a unique opportunity to isolate elusive species in self-assembly processes that are too reactive to both "see" and "capture".