Structural flexibility of halogen bonds showed in a single-crystal-to-single-crystal [2+2] photodimerization.
Structural flexibility of halogen bonds showed in a single-crystal-to-single-crystal [2+2] photodimerization.
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DOI：
10.1107/s2052252518007583
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发表时间：
2018-07-01
期刊：
影响因子：
3.9
通讯作者：
MacGillivray LR
中科院分区：
文献类型：
--
作者：
Sinnwell MA;Blad JN;Thomas LR;MacGillivray LR
对于有机固体来说，单晶到单晶（SCSC）反应很少见。我们描述了由卤素键介导的 SCSC [2+2] 光二聚化的第一个例子。卤素键已成为控制有机固体中分子组装的非共价力，其可靠性与氢键类似。尽管卤素键的结构导向作用经常与氢键进行比较，但有关卤素键基本结构行为的一般知识的发展机会有限。在对涉及有机合成和光响应材料开发的固态反应进行研究之后，这项工作证明了分子间 N⋯I 卤键（晶体工程师的“主力”相互作用）成分支持单晶到单晶 [2+2] 光二聚化的能力。对单晶反应中卤素键合组分所经历的几何变化与来自剑桥结构数据库的当前 N⋯I 卤素键晶体景观进行了比较。具体来说，观察到卤素键合组分的线性到弯曲类型的变形，这有望支持含有可以在密排晶体环境中进行运动的分子的功能性卤素键合材料的开发。
Single-crystal-to-single-crystal (SCSC) reactions are rare for organic solids. We describe the first example of an SCSC [2+2] photodimerization that is mediated by halogen bonding. Halogen bonds have emerged as noncovalent forces that govern the assembly of molecules in organic solids with a degree of reliability akin to hydrogen bonds. Although the structure-directing roles of halogen bonds are often compared to hydrogen bonds, general knowledge concerning the fundamental structural behavior of halogen bonds has had limited opportunity to develop. Following an investigation of solid-state reactions involving organic syntheses and the development of photoresponsive materials, this work demonstrates the ability of the components of intermolecular N⋯I halogen bonding – a ‘workhorse’ interaction for the crystal engineer – to support a single-crystal-to-single-crystal [2+2] photodimerization. A comparison is provided of the geometric changes experienced by the halogen-bonded components in the single-crystal reaction to the current crystal landscape of N⋯I halogen bonds, as derived from the Cambridge Structural Database. Specifically, a linear-to-bent type of deformation of the halogen-bonded components was observed, which is expected to support the development of functional halogen-bonded materials containing molecules that can undergo movements in close-packed crystal environments.