in tetrahydrofuran byproducts: LiCl; dropwise addn. of CpLi in THF to (PMePh2)2FeCl2 in THF under Ar at -10°C; 36 h at -10°C;; evapn. at -10°C (vac.); dissolving inn toluene; filtered; addn. of pentane to filtrate; filtered; evapn. of filtrate; addn. of toluene/pentane; crystn. within 9 d at -20°C; further crystn. from mother liquor;;