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NMR spectroscopy of organolithium compounds. XXVI —The aggregation behaviour of methyllithium in the presence of LiBr and LiI in diethyl ether and tetrahydrofuran
Author(s) -
Fox Thomas,
Hausmann Heike,
Günther Harald
Publication year - 2004
Publication title -
magnetic resonance in chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0749-1581
DOI - 10.1002/mrc.1443
Subject(s) - methyllithium , chemistry , tetrahydrofuran , bromide , diethyl ether , deuterium , ether , lithium (medication) , nuclear magnetic resonance spectroscopy , iodide , dimer , chemical shift , halogen , medicinal chemistry , organic chemistry , alkyl , solvent , medicine , physics , quantum mechanics , endocrinology
1 H, 6 Li and 13 C NMR spectroscopy were used to determine the structure of aggregates formed in mixtures of methyllithium, H 3 CLi, and lithium bromide and iodide in diethyl ether and tetrahydrofuran. From the chemical shifts, the signal intensity distribution and the isotope shifts observed for partially deuterated systems, it was shown that generally tetrameric structures with different halogen contents dominate. For methyllithium–lithium bromide (1:1) in THF a considerable concentration of an H 3 CLiLiBr dimer was found. For the first time, deuterium‐induced 6 Li isotope shifts over four bonds were observed. Copyright © 2004 John Wiley & Sons, Ltd.