Department of Organic Chemistry and Technology, Budapest University of Technology and Economics, H-1521, Budapest, PO Box 91, Hungary.
Org Biomol Chem. 2010 Mar 7;8(5):947-59. doi: 10.1039/b917564d. Epub 2010 Jan 6.
Non-racemic enantiomeric mixtures form homochiral and heterochiral aggregates in melt or suspension, during adsorption or recrystallization, and these diastereomeric associations determine the distribution of the enantiomers between the solid and other (liquid or vapour) phases. That distribution depends on the stability order of the homo- and heterochiral aggregates (conglomerate or racemate formation). Therefore, there is a correlation between the binary melting point phase diagrams and the experimental ee(I)vs. ee(0) curves (ee(I) refers to the crystallized enantiomeric mixtures, ee(0) is the composition of the starting ones). Accordingly, distribution of the enantiomeric mixtures between two phases is characteristic and usually significant enrichment can be achieved. There are two exceptions: no enrichment could be observed under thermodynamically controlled conditions when the starting enantiomer composition corresponded to the eutectic composition, or when the method used was unsuitable for separation. In several cases, when kinetic control governed the crystallization, the character of the ee(0)-ee(I) curve did not correlate with the melting point binary phase diagram.
非对映异构体混合物在熔融或悬浮状态下、吸附或重结晶过程中形成同手性和异手性聚集体，这些非对映异构体缔合决定了对映异构体在固相与其他（液相或气相）相之间的分布。这种分布取决于同手性和异手性聚集体（外消旋体形成）的稳定性顺序。因此，二元熔点相图和实验 ee(I)vs.ee(0)曲线之间存在相关性（ee(I) 是指结晶的对映异构体混合物，ee(0) 是起始混合物的组成）。因此，对映异构体混合物在两相之间的分布是特征性的，通常可以实现显著的富集。有两个例外：当起始对映体组成对应于共晶组成或使用的方法不适合分离时，在热力学控制条件下不会观察到富集；在几种情况下，当动力学控制主导结晶时，ee(0)-ee(I)曲线的特征与熔点二元相图不相关。
