carbon 4 of the sugars (when these were present in the pyranose ring form) and the predominant [Tb(pydca)3]3– enantiomer. This suggests that an association process does indeed lead to the observed Pfeiffer effects, and that the forces leading to the formation of the outer-sphere complexes are rather specific in nature.
在与
单糖醛糖形成外球络合物后,在[Tb(pydca)3 ] 3–(pydca =
吡啶-2,6-二
羧酸吡啶)的外消旋混合物中诱导了光学活性,并通过圆偏振发光光谱法对其进行了研究。将D-
甘油醛添加到[Tb(pydca)3 ] 3–的溶液中未观察到光学活性,这表明存在
半缩醛环氧是发生外球缔合所必需的。发现诱导的光学活性的符号随所用糖的身份而变化,但是在糖的碳原子4(当它们以
吡喃糖环形式存在时)的构型与主要的[Tb( pydca)3 ] 3–对映异构体。这表明缔合过程确实导致了观察到的
菲佛效应,并且导致形成外圈复合物的力在本质上是相当特殊的。