cyclopentadienylsodium in tetrahydrofuran 1:1 mixt. of CpNa and 2,4-Me2C5H5K in THF was slowly added under N2 at -78°C to a slurry of FeCl2 in THF, mixt. was slowly warmed to room temp. and stirred for 1 h; 1:1:2 mixt. of Cp2Fe, Fe(2,4-Me2C5H5)2 and CpFe(2,4-Me2C5H5) was obtained; evapd., extd. with pentane, filtered, evapd., dissolved in a min. vol. of pentane, cooled to -20 to -40°C (nearly all of both Cp-complexes crystd.), ppt. dissolved in a min. of pentane, cooled slowly to -20°C, crystals sepd.; elem. anal.;

in tetrahydrofuran N2-atmosphere; addn. of equimolar mixt. of ligands to FeCl2 (-78°C), slow warming to room temp., stirring for 1 h; solvent removal (vac.), extn. into hexane, filtration, solvent removal (vac.), chromy. (Al2O3, 2percent THF in hexane);