Recent developments in cyclopentadienyl-alkalimetal chemistry

Cyclopentadienyl-alkalimetal compounds are among the first organometallic compounds prepared. Their structures have been well studied and generally show unsolvated or solvated polymer chains or solvated monomers. During the last few years there have been some interesting developments in the structural chemistry of this compound class; structures of oligomeric species and anionic metallocene sandwich complexes have been reported. This work discusses bonding in Cp-alkalimetal compounds and summarizes selected structural data of all Cp-alkalimetal compounds published up to September 1997 including our own unpublished results (the indenyl, fluorenyl and higher delocalized systems have been excluded deliberately and are only mentioned occasionally for comparison). (C) 1998 Elsevier Science S.A. All rights reserved.