Premium
Characterization of Hexameric and Octameric sec ‐Butyllithium/ sec ‐Butoxide Mixed Aggregates
Author(s) -
Su Chicheung,
Hopson Russell,
Williard Paul G.
Publication year - 2013
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.201300749
Subject(s) - chemistry , random hexamer , butyllithium , toluene , nuclear magnetic resonance spectroscopy , tetramer , organic chemistry , crystallography , enzyme
Solution‐state characterization of sec ‐butyllithium in [D 8 ]toluene was conducted by utilizing a variety of NMR spectroscopic experiments including diffusion‐ordered NMR spectroscopy (DOSY) with diffusion‐coefficient–formula‐weight correlation analyses and other one‐ and two‐dimensional NMR spectroscopic techniques. These results suggest that sec ‐butyllithium exists primarily as a tetramer/hexamer mixture in hydrocarbon solvents. However, the presence of roughly 2–5 % (by mol ratio) lithium sec ‐butoxide in both commercially available and laboratory‐synthesized sec ‐butyllithium solutions due to the reaction with adventitious dioxygen will lead to the formation of a 1:5 sec ‐butoxide/ sec ‐butyllithium mixed hexamer. A sec ‐butoxide/ sec ‐butyllithium mixed octamer will emerge when the proportion of butoxide to butyllithium increases.