π-Stacking induced NMR spectrum splitting in enantiomerically enriched Ru(II) complexes:: Evaluation of enantiomeric excess

被引：37

作者：

Bergman, SD ^{[1
]}

Kol, M ^{[1
]}

机构：

[1] Tel Aviv Univ, Raymond & Beverly Sackler Fac Exact Sci, Sch Chem, IL-69978 Tel Aviv, Israel

来源：

INORGANIC CHEMISTRY | 2005年 / 44卷 / 06期

关键词：

D O I：

10.1021/ic048569e

中图分类号：

O61 [无机化学];

学科分类号：

070301 ; 081704 ;

摘要：

Several chiral octahedral complexes of the general formula [Ru(bpy)(2)(Lig)][PF6](2) (Lig = a ligand that can participate in pi-stacking interactions such as eilatin, isoeilatin, and tpphz) were synthesized in both the racemic and enantiomerically pure/enriched forms. Nonracemic mixtures of enantiomers of all these complexes exhibit splitting of the H-1 NMR spectra (NMR nonequivalence); i.e., each spectrum contains a major and a minor set of peaks. The origin of this phenomenon is attributed to a fast equilibrium between monomers and discrete dimers held together by pi-stacking interactions, and it is observed for a wide range of pi-stacking interaction strengths. The NMR spectrum splitting exhibited by these complexes can be exploited for the evaluation of their enantiomeric excess simply from the integral ratio, without addition of chiral shift reagents.

引用

页码：1647 / 1654

页数：8

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