7Li solid-state NMR of lithium amides: structural information from 7Li quadrupolar coupling constants

✍ Scribed by Michael Hartung; Harald Günther; Jean-Paul Amoureux; Christian Fernandéz

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 333 KB
• Volume: 36
• Category: Article
• ISSN: 0749-1581
• DOI: 10.1002/(sici)1097-458x(199806)36:13<s61::aid-omr319>3.0.co;2-d

✦ Synopsis

Lithium-7 quadrupolar coupling constants, s(7Li), were measured for a number of microcrystalline lithium amides by solid-state 7Li magic angle spinning (MAS) NMR. A linear correlation between s(7Li) and the structural NÈLiÈN angle known from x-ray di †raction work was found : s(7Li) \ (4.1 ^0.5) ‡ NÈLiÈN [ (110.8 ^69.0). On this basis, structural information for new systems becomes available. For the polymer material a ladder structure is proposed. The n-Ñip of the Ðve-membered metallacycle formed by the

2 by 13C cross-polarization/MAS DNMR spectroscopy. From the analysis of the temperature-dependent lineshape of the methyl signals, a barrier of kJ mol~1 was derived for this rotational process in the solid, which *GE(293) \ 66 compares favourably with data derived for related compounds.