DDT Polymorphism and the Lethality of Crystal Forms
DDT Polymorphism and the Lethality of Crystal Forms
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DOI：
10.1002/anie.201703028
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发表时间：
2017-08-14
影响因子：
16.6
通讯作者：
Kahr, Bart
中科院分区：
文献类型：
--
作者：
Yang, Jingxiang;Hu, C. T.;Kahr, Bart
滴滴涕（1，1，1-三氯-2，2-双（4-氯苯基）乙烷）是一种接触性杀虫剂，自1939年发现其活性以来，历史悠久，一直被认为是单态的。在此，我们报道了第二种多晶型物的发现和表征，称为II型，其可以作为单晶分离，但在室温下非常缓慢地转化为先前报道的形式，现在称为I型。基于晶体结构预测的进化算法的计算显示，I型和II型是计算的50种最低能量晶体结构中的四种。对果蝇（Drosophila melanogaster）的接触杀虫活性的初步研究表明，二型的活性更强，这表明有可能研制出更有效的固态制剂，从而减少滴滴涕的用量，从而最大限度地减少对环境的影响。
DDT (1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane), a contact insecticide with a rich and controversial history since its activity was discovered in 1939, has long been thought to be monomorphic. Herein we report the discovery and characterization of a second polymorph, designated Form II, which can be isolated as single crystals, but converts very slowly at room temperature to the form reported previously, now designated as Form I. Computations based on an evolutionary algorithm for crystal structure prediction revealed that Forms I and II are among the four lowest energy crystal structures of fifty calculated. A preliminary study of the contact insecticidal activity toward fruit flies (Drosophila melanogaster) indicates that Form II is more active, suggesting opportunities for more effective solid-state formulations that would allow reduced amounts of DDT, thereby minimizing environmental impact.