X-RAY CRYSTAL-STRUCTURE OF A VINYLLITHIUM TETRAHYDROFURAN SOLVATE (C2H3LI-THF)4 - QUANTITATIVE ESTIMATION OF LI-H DISTANCES BY LI-6-H-1 HOESY

Vinyllithium crystallizes with one equivalent of tetrahydrofuran (thf) and is tetrameric in the solid state whereas in thf solution a tetramer-dimer equilibrium (8:1, 2.0 mol dm-3, -90-degrees-C) is present; lithium-hydrogen distances in solution are derived quantitatively by Li-6-H-1 HOESY with ca. 0.2 angstrom accuracy.