Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853-1301, USA.
J Am Chem Soc. 2009 Sep 16;131(36):13142-54. doi: 10.1021/ja9047784.
The method of continuous variation in conjunction with (6)Li NMR spectroscopy was used to characterize lithium phenolates solvated by tetrahydrofuran and 1,2-dimethoxyethane. The strategy relies on the formation of ensembles of homo- and heteroaggregated phenolates. The symmetries and concentration dependencies of the heteroaggregates attest to the aggregation numbers of the homoaggregates. The structurally diverse phenols afford substrate- and solvent-dependent combinations of lithium phenolate monomers, dimers, trimers, tetramers, and pentamers. We discuss the refinement of protocols for characterizing O-lithiated species. Computational studies examine further the substituent and solvent dependencies of aggregation.
采用连续变化法结合 (6)Li NMR 光谱法,对四氢呋喃和 1,2-二甲氧基乙烷溶剂化的苯酚锂进行了表征。该策略依赖于同聚和共聚苯酚盐的形成。杂聚体的对称性和浓度依赖性证明了同聚体的聚集数。结构多样的苯酚提供了底物和溶剂依赖性的锂苯酚盐单体、二聚体、三聚体、四聚体和五聚体组合。我们讨论了完善 O-锂化物种表征方案的问题。计算研究进一步考察了聚集的取代基和溶剂依赖性。