Charge Density of Intra- and Intermolecular Halogen Contacts
Charge Density of Intra- and Intermolecular Halogen Contacts
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分子内和分子间卤素接触的电荷密度
DOI：
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
U. Englert
中科院分区：
文献类型：
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作者：
Ruimin Wang;T. Dols;C. Lehmann;U. Englert
尽管几十年前已有充分记录，但涉及卤素原子的非常短的接触，最近发现人们对晶体工程中潜在相关的兴趣日益浓厚。具有足够质量和分辨率的 X 射线衍射数据允许通过实验确定具有此类接触特征的晶体中的电荷密度，从而将这一可观察到的量与分子堆积的影响联系起来。报告了电荷密度研究的结果，涵盖了卤素间接触的距离范围比单纯的范德华接触明显短和长得多，并讨论了它们与所研究化合物的晶体化学的相关性。分子内和分子间 Cl·Cl 相互作用的第一个趋势表明，这些接触中最短的接触距离为 ca。 3.2 A，可以与弱氢键竞争。
Remarkably short contacts involving halogen atoms, although well documented decades ago, have recently found increasing interest as potentially relevant in the context of crystal engineering. X-ray diffraction data of sufficient quality and resolution allow to experimentally determine the charge density in crystals featuring such contacts and hence to associate this observable quantity with effects of molecular packing. Results from charge density studies covering interhalogen contacts over a distance range significantly shorter and considerably longer than mere van-der-Waals contacts are reported, and their relevance for the crystal chemistry of the compounds under investigation is discussed. A first trend for intra- and intermolecular Cl···Cl interactions indicates that the shortest among these contacts, with a distance of ca. 3.2 A, can compete with weak hydrogen bonds.