681812-01-1Relevant articles and documents
The Bis(η6-benzene)lithium Cation: A Fundamental Main-Group Organometallic Species
Daniliuc, Constantin G.,Eckert, Hellmut,Erker, Gerhard,Hansen, Michael Ryan,Jie, Xiaoming,Kehr, Gerald,Li, Jun,Mück-Lichtenfeld, Christian,Wübker, Anna-Lena
supporting information, p. 22879 - 22884 (2021/09/14)
The synthesis and characterization of the bis(η6-benzene)lithium cation, the benzene metallocene of the lightest metal, is reported. The boron compound FmesBCl2 [Fmes: 2,4,6-tris(trifluoromethyl)phenyl] reacted with three molar equivalents of the lithio-acetylene reagent Li-C≡C-Fmxyl [Fmxyl: 3,5-bis(trifluoromethyl)phenyl]. Subsequent crystallization from benzene gave the [bis(η6-benzene)Li]+ cation with the [{FmesB(-C≡C-Fmxyl)3}2Li]? anion. This parent [(arene)2Li]+ cation shows an eclipsed arrangement of the pair of benzene ligands at the central lithium cation with uniform carbon-lithium bond lengths. The corresponding [(η6-toluene)2Li]+ and [(η6-durene)2Li]+ containing salts were similarly prepared. The bis(arene)lithium cations were characterized by X-ray diffraction, by solid-state 7Li MAS NMR spectroscopy and their bonding features were analyzed by DFT calculations.