title: Solid-state structure of a Li/F carbenoid: pentafluoroethyllithium.
abstract: Lithium carbenoids are versatile compounds for synthesis owing to their intriguing ambiphilic behavior. Although this class of compounds has been known for several years, few solid-state structures exist because of their high reactivity and often low thermal stability. Using cryo X-ray techniques, we were now able to elucidate the first solid-state structure of a Li/F alkyl carbenoid, pentafluoroethyllithium (LiC2F5), finally yielding a prototype for investigating structure-reactivity relationships for this class of molecules. The compound forms a diethyl ether-solvated dimer bridged by a rare C-F-Li link. Complementary NMR spectroscopy studies in solution show dynamic processes and indicate rapid exchange of starting material and product. Theoretical investigations help to understand the formation of the observed unusual structural motif.
authors.affiliation: Centrum für Molekulare Materialien CM2, Fakultät für Chemie, Universität Bielefeld, Universitätsstrasse 25, 33615 Bielefeld (Germany).
authors.forename: Benedikt
authors.initials: B
authors.lastname: Waerder
authors.forename: Simon
authors.initials: S
authors.lastname: Steinhauer
authors.forename: Beate
authors.initials: B
authors.lastname: Neumann
authors.forename: Hans-Georg
authors.initials: HG
authors.lastname: Stammler
authors.forename: Andreas
authors.initials: A
authors.lastname: Mix
authors.forename: Yury V
authors.initials: YV
authors.lastname: Vishnevskiy
authors.forename: Berthold
authors.initials: B
authors.lastname: Hoge
authors.forename: Norbert W
authors.initials: NW
authors.lastname: Mitzel
keywords: aggregation; carbenoid; crystal structure; fluorine; lithium