in tetrahydrofuran byproducts: LiCl; dropwise addn. of CpLi in THF to (PMe2Ph)2FeCl2 in THF under Ar at 20.dedree.C;; evapn. (vac.); dissolving in pentane; filtration; dissolving of the solid in CH2Cl2; filtration from LiCl; pptn. from filtrate by addn. of pentane, repeating operation; elem. anal.; Cp2Fe from the pentane filtrate and the THF distillate by sublimation;;