外消旋體

外消旋体(英語:racemate)是等物质的量的一对对映体混合后得到的组成物。第一个制得的外消旋体是路易·巴斯德制得的酒石酸的外消旋混合物。[1]

性质

由于内部组成成分使不同方向的等量平面偏振光偏转抵消,因此外消旋体旋光度为零。并且,虽然对映体的物理性质一般相同,但外消旋体的物理性质如熔点溶解度等与对应的对映体性质常常是不相同的。

根据药物的不同,有些药物是其多个对映体之一,而有些药物则为外消旋体。事前必须就药物对映体的药理学效果作验证,以减少危险发生。

外消旋体还可细分为:

  • 外消旋化合物(英語:racemic compound):左旋体与右旋体分子之间有较大亲和力,两种分子在晶胞中配对,形成计量学上的化合物晶体。它们熔点多数高于纯旋光体,溶解度则低于纯旋光体。
  • 外消旋混合物(英語:racemic mixture):纯旋光体之间的亲和力更大,左旋体与右旋体分别形成晶体。它们熔点通常低于纯旋光体,溶解度则高于纯旋光体。
  • 外消旋固體溶液(英語:racemic solid solution):纯旋光体之间,与对映体之间的亲和力比较接近,两种构型分子排列混乱。熔点、溶解度和纯旋光体比较接近。

拆分

合成物

参见

註釋

  1. ^ Moss, Gerry P. Basic terminology of stereochemistry (IUPAC Recommendations 1996). Department of Chemistry, Queen Mary University of London: Blackwell Scientific Publications. 1996: 8,11 [2014-08-10]. (原始内容存档于2006-12-07). 

参考资料

  • 邢其毅、裴偉偉、徐瑞秋、裴堅。《基础有机化学》第四版上册。北京:高等教育出版社,2016年6月。ISBN 978-7-301-27212-1
  • Илиел Э., Вайлен С., Дойл М. Основы органической стереохимии. М.: Бином. Лаборатория знаний. Пер. с англ. З. А. Бредихиной, под ред. А. А. Бредихина. 2007 [Basic Organic Stereochemistry]. ISBN 978-5-94774-370-8 (俄语).  (俄文)
  • Потапов В. М. Стереохимия. М: Химия. 1988. ISBN 5-7245-0376-X (俄语).  (俄文)

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