Organic Chemistry Ferrocene Lab

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Experiment 42: Ferrocene Preparation

Introduction:
The purpose of the lab is to prepare ferrocene from ferrous chloride and cyclopentadiene. Ferrocene, an organometallic, is a combination of two cyclopentadienide ions with a ferrous cation, such that the six pi electrons binds every carbon equally to the metal forming a sandwich type structure. Ferrocene has the properties of both an activated benzene (undergoes electrophilic substitution reactions) and a ferrous ion (oxidation reaction). Glyme and DMSO are used as solvents as they have moderate polarity so they would break up KOH into K+ and OH-, without breaking the hydrogen bonding in the hydroxide ion. Cyclopentadiene is relatively acidic so a strong base would be needed to abstract a proton to form the cyclopentadienide anion (OH- from KOH).

Procedure:
8 g of potassium hydroxide, 20 mL of 1,2-dimethoxyethane, and 2 ml of cyclopentadiene were added to a 100 ml round bottom flask. The mixture was swirled for 10 minutes. 2.4 g of ferrous chloride hydrate and 12 ml of dimethyl sulfoxide were added to a 125 ml Erlenmeyer flask. The FeCl2 was warmed in a warm water bath for five minutes, and then cooled in an ice bath until 10°C was reached. The solution was then transferred into a separatory funnel, and was added to the round bottom flask solution dropwise over ten minutes while agitating.

The contents of the round bottom flask were poured into a beaker with 40 g of ice and 35 ml of 6M HCl. The flask was then rinsed with three 20 mL portions of water, and poured into the beaker. The solution was filtered through a Buchner funnel, and washed with 20 ml of cold water.

FLOWCHART IS SHITTY

Table of chemicals:
Chemical| Quantity| MW or % Comp|
KOH| 8.071 g| 56.12 g/mol|
C4H10O2| 20.7 mL| 90.12 g/mol|
C5H6| 2 mL| 66.1 g/mol|
FeCl2| 2.413 g| 126.75 g/mol|
DMSO| 12 mL| 78.13 g/mol|
HCl| 35 mL| 6M|
H2O| (3x) 20 mL; 20 mL wash| 18.01 g/mol|

Mechanism:
ANU...
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