Enantiomeric self-resolution

Self-resolution of Enantiomeric Molecules 3.2.1 Enantiomeric self-resolution on crystallisation... 

The helical tubuland (HT) diols are a group of alicyclic dialcohols that show characteristic crystallisation behaviour [32,35], When a racemic sample is crystallised, then enantiomeric self-resolution occurs, yielding a conglomerate of (+)- and... 

Enantiomeric self-resolution through guest complexation... 

Enantiomeric self-resolution through complexation with a hydrogen-bonding guest solvent has interesting potential as a means of separation. Unfortunately, little prediction of new examples seems possible with our current level of understanding. 

A related phenomenon can also occur when the crystal lattice packing is chiral. This intrinsic handedness can result in formation of a 1 1 mixture of enantiomeric crystals. In this case, although there has been self-resolution into (+)- and (—)-crystals, both molecular enantiomers remain unseparated in each crystal. The fundamental distinction is that a conglomerate single crystal contains only one molecular enantiomer and therefore would be optically active in solution, while, for the latter, a single crystal contains both molecular enantiomers and its solution would be optically inactive. 

Self-resolution of Enantiomeric Crystals Containing Both Enantiomeric Molecules... 

Surprisingly little work has been carried out on the resolution of homochiral helicates into the two enantiomers. Self-resolution upon crystallization has been observed for two homonuclear triple helicates [37,38], but there seem to be only two well-authenticated cases of enantiomeric resolution, both using antimonyl tartrate the complex [ 02(9)3] " , a dinuclear triple helix [39], and a trinuclear double helical complex of iron(ll) [Fe3(19)2] " with a tm-terpyridyl ligand [40]. The circular dichroism spectrum of [ 02(9)3] " is shown in Figure 13. 

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