Natural-abundance lithium-6 NMR spin–lattice relaxation in some simple organolithium compounds

✍ Scribed by F. W. Wehrli

• Publisher: John Wiley and Sons
• Year: 1978
• Tongue: English
• Weight: 258 KB
• Volume: 11
• Category: Article
• ISSN: 0749-1581
• DOI: 10.1002/mrc.1270110210

✦ Synopsis

Abstract

^6^Li, ^7^Li and ^13^C spin–lattice relaxation and NOE data are reported for methyllithium, butyllithium and phenyllithium with ^6^Li T~1~ values found in the order of tens of seconds and their relaxation 2–3 orders of magnitude less efficient than that for ^7^Li. The data indicate that ^6^Li is substantially relaxed by the intramolecular ^6^Li–^1^H mechanism, whereas both quadrupolar and ^6^Li–^7^Li dipolar relaxation are minor processes. The non‐linearity of the Arrhenius curve for Me^6^Li is compatible with a small spin–rotation contribution. Since ^6^Li in solution behaves essentially as a spin‐1/2 nucleus, it represents, in spite of its lower magnetic moment and overall sensitivity, an attractive alternative to ^7^Li NMR.