Conformers and Rotamers of (±)-trans-2,3-Bis(2-naphthyl)-15-crown-5 and -18-crown-6 and Their Alkali Metal Complexes
作者:A. Merz、L. Gromann、A. Karl、L. Parkanyi、O. Schneider
DOI:10.1002/(sici)1099-0690(199802)1998:2<403::aid-ejoc403>3.0.co;2-q
日期:1998.2
The conformations of (±)-trans-2,3-Bis(1-naphthyl)-15-crown-5 (1) and -18-crown-6 (2) are investigated by MM2 and dynamic 1H-NMR spectroscopy. The most stable conformation is the diequatorial one in both the free ligands and the alkali metal complexes 1 · NaClO4 and 2 · KClO4. Three rotamers, pseudo-aa, pseudo-ee, and pseudo-ae, with respect to the spatial arrangement of the naphthyl groups, were found
(±)-trans-2,3-Bis(1-naphthyl)-15-crown-5 (1) 和 -18-crown-6 (2) 的构象通过 MM2 和动态 1H-NMR 光谱研究。最稳定的构象是游离配体和碱金属配合物 1·NaClO4 和 2·KClO4 中的双赤道构象。三个旋转异构体,pseudo-aa、pseudo-ee 和pseudo-ae,在萘基的空间排列方面,通过MM2 计算的最小值和低温NMR 实验发现,与旋转势垒相当一致。在阳离子增强的牙冠中,旋转速率显着降低。旋转异构体的分布取决于牙冠的大小及其状态,游离的或复合的。