Synthesis of Ferrocene

Ferrocene is a stable, yellow organometallic compound, C10H10Fe. When it was first discovered in 1951 there was a considerable amount of debate about the structure of this compound.

The solution of make Ferrocene as following : Quickly transfer the finely ground powder to a round bottom flask that was previously flushed with N2 gas and equipped with a magnetic stirring bar, followed by 2.0 mL of 1,2-dimethoxyethane (Glyme). Using a syringe, add 0.20 mL (2.4 mmol) of the freshly distilled cyclopentadiene directly to the mixture of KOH in Glyme. Stir the flask vigorously.

While the potassium cyclopentadienide is forming, prepare a solution of 0.24g (7.4 mmol) of FeCl2 4H2O in 1.2 mL (graduated cylinder) of DMSO. Using a Pasteur pipet transfer the FeCl2 4H2O solution dropwise to the cyclopentadienide solution prepared above. The addition should be carried out slowly, over a period of approximately 10 min. Stir the solution continuously for 15-20 min. to complete the reaction. Transfer the materials to an Erlenmeyer flask.

Prepare a mixture of 4.0 g of ice and 3.5 mL of 6M HCl in a graduated cylinder and add this mixture to the Erlenmeyer flask. Stir the mixture thoroughly to neutralize any remaining KOH (if necessary add more HCl, test with pH paper). Filter the orange crystals of product using a Hirsch funnel and wash the crystal with two 1mL portions of water. Draw air through the product on the Hirsch funnel for 5 min., dry the crystals between the folds of filter paper, and finally dry the product on a filter paper. Calculate the percentage yield and determine the melting point. This product, when dry, is quite satisfactory for subsequent reactions.