T. Matsuo et al., THE FIRST ISOLATION AND FULL CHARACTERIZATION OF FULVENE DIANION - SYNTHESIS AND X-RAY STRUCTURE OF DILITHIUM HEXASILYLFULVENE DIANION, Organometallics, 17(15), 1998, pp. 3143-3145
Treatment of hexasilylfulvene (4) with lithium metal in, tetrahydrofur
an yields yellow crystals of the dilithium hexasilylfulvene dianion (5
). The dilithium hexasilylfulvene dianion (5) has a monomeric structur
e and forms a contact ion pair (bis-CIP) in the crystals. One of the l
ithium atoms is located above the center of the five-membered ring, wh
ereas the other one is bonded to the exocyclic carbon atom. The bis-CI
P structure determined by X-ray crystallography is maintained in solut
ion.