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Published November 5, 1980 | public
Journal Article

Natural-Abundance ^(15)N Nuclear Magnetic Resonance Spectroscopy of Coronands, Cryptands, and Some of Their Complexes with Diamagnetic Metal Ions

Abstract

Natural-abundance I5N nuclear magnetic resonance spectra of nitrogen-containing crown ethers, cryptand ligands, and other ligands with pyridine-type nitrogens and their complexes with alkali, alkaline-earth, silver(I), and thallium(I) ions are reported. The complexation shifts tend to go downfield with increasing charge and increasing ionic character of the nitrogen-to-metal-ion bond but upfield with increasing polarizability of the ion. The downfield shifts are generally more pronounced if the ions fit tightly into the cyclic ligand. For those metal ions expected to form essentially covalent bonds to nitrogen, the complexation shifts are not easily predicted. Some of the thallium- and silver-cryptate complexes display sizable one-bond ^(15)N-metal couplings.

Additional Information

© 1980 American Chemical Society. Received March 18, 1980. Supported by the National Science Foundation and by the Public Health Service, Grant No. GM-11072 from the Division of General Medical Sciences. NATO Postdoctoral Fellow, 1976-1977. We thank Professor Dr. F. Vogtle and coworkers for samples of ligands and also Professor S. I. Chan for helpful discussions.

Additional details

Created:
August 19, 2023
Modified:
October 24, 2023