Question

Synthesis and Separation of Ferrocenes
Pre-Lab Question:
1. Work up of acetylation, you'll be adding 10% NAOH to the aqueous phase until it is neutral. Why is it acidic in the first place?

2. Product mixture that contains leftover ferrocene, monoacetylferrocene, and diacetylferrocene. Draw a developed TLC plate spotted with this mixture is likely to look like & which spot is which.

Answer 1

1) In acetylation, acetyl halide in general, Acetyl Chloride in particular, is used as precursor. During the reaction HX in general, HCl in particular is evolving as the side product.

Ferrocene + Acetyl Chloride -----------> Aectyl Ferrocene + HCl

So , the water layer is acidic which require NaOH to neutrilize.

2) In the TLC plate,

RF valur will be very high for Ferrocene ( non polar)

RF will be low for Acetyl ferrocene and very low for Diactyl ferrocene

So, Diactyl ferrocene will be in down, actyl ferrocene in middle and Ferrocene will be in Top.