Highly Twisted Ethylene Dianion Dilithium Stabilized by Phenyl and Sillyl Groups

Article abstract of DOI:10.1246/bcsj.68.3215

Phenyl- and silyl-substituted ethylene dianion dilithiums, <1-phenyl-1,2,2-tris(trimethylsilyl)ethylene> (2) and <1,1-diphenyl-2,2-bis(trimethylsilyl)ethylene> (4), were prepared an characterized by X-ray crystallography as well as NMR spectra.The crystal structures of 2 and 4 revealed interesting structural features.One of the lithium cations was located near to the two central carbon atoms, ipso and ortho carbons of the phenylring, while the other one was found above the benzene ring.The central C-C bond is twisted by ca. 90 deg for 2 and ca. 70 deg for 4.