Acylation of Ferrocene
Objective:
The objective of this lab was to carry and observe the acylation of colorful organometallic compound and purify the product by chromatography. In In this experiment, we carried out the Friedel-Crafts acylation of ferrocene to produce acetylferrocene. The Friedel-Crafts reaction is very useful in the synthesis of carbon-carbon bonds. The reaction and the mechanism are shown below:
Table of Chemical and Physical Properties:
Name
Structure
MW
Chemical and Physical Properties
Ferrocene
186
Boiling Point: 249
Melting Point 172-174
Appear as yellow-orange color
Acetic Anhydride
Discussion: Phosphoric acid was added to catalyze the reaction. The Sodium Hydroxide was used to neutralize the product. Silica gel was used as the stratrorory phase in the column chromatography. Hexane and 50:50 hexane/anhydrous diethyl ether were used depending on the polarity of the desired fraction. We have very high percent yield (about 173.2%). I think this happen because our product was not fully fried. Also, there is possibility chance that we have made the bi-products due to the timing in this reaction. Beside the desired products, the bi-product can be made in this reaction is diacetyl ferrocene. Also, some of the ferrocene didn’t react in this reaction. Because the product we obtained in this reaction is the composition of three ferrocene products. The products have different polarity (some of the products is nonpolar) so that they would travel differently on the Rf. The polar molecules travel the median distance between non-polar ferrocene and polar acetyl ferrocene. The IR of our product shows the peak at 1651.63 which is the C=O. The peak at 3097.69 and 3069.26 are the overlapped caused by the ferrocene. The acetyl ferrocene ring stretch is at about 892.77 cm-1‑ The melting range of our products is 80-83oC. Conclusion: We were successful in making acetyl ferrocene based on the IR and TLC. The percent yield of our product in this reaction is about 173.2%. The melting range of our product is 80-83oC. The Rf value we got from the first week of reaction is 0.28 while the Rf of the second week is 0.0.19. Post-lab discussion
1) Hexane was the first column since it is a nonpolar element. Then, the ferrocene would leave the column
