K-39 Quadrupolar and Chemical Shift Tensors for Organic Potassium Complexes and Diatomic Molecules

详细信息    查看全文

• 作者：Philip K. Lee ; Rebecca P. Chapman ; Lei Zhang ; Jiaxin Hu ; Leonard J. Barbour ; Elizabeth K. Elliott ; George W. Gokel ; David L. Bryce
• 刊名：Journal of Physical Chemistry A
• 出版年：2007
• 出版时间：December 20, 2007
• 年：2007
• 卷：111
• 期：50
• 页码：12859 - 12863
• 全文大小：111K
• 年卷期：v.111,no.50(December 20, 2007)
• ISSN：1520-5215

文摘

Solid-state potassium-39 NMR spectra of two potassium complexes of crown-ether-based organic ligands(1·KI and 2) have been acquired at 11.75 and 21.1 T and interpreted to provide information on the³⁹K quadrupolar and chemical shift tensors. The analyses reveal a large potassium chemical shift tensorspan of 75 ± 20 ppm for 1·KI. This appears to be the first such measurement for potassium in anorganic complex, thereby suggesting the utility of potassium chemical shift tensors for characterizing organicand biomolecular K⁺ binding environments. Compound 2 exhibits a cation- interaction between K⁺ and aphenyl group, and therefore, the ³⁹K NMR tensors obtained for this compound must bepartly representative of this interaction. Analyses of potassium-39 spin-rotation data for gaseous ³⁹K¹⁹Fand ³⁹K³⁵Cl available from molecular beam experiments performed by Cederberg and co-workers revealthe largest potassium CS tensor spans known to date, 84.39 and 141 ppm, respectively. Collectively, theresults obtained highlight the potential of ultrahigh-field potassium-39 solid-state NMR spectroscopy and, inparticular, the wide range of the anisotropy of the potassium CS tensor when organic and diatomic systemsare considered.