Short History on Organometallics

What characterizes an organometallic compound?

m-C bond

- transition metal bonded to carbon

The First organometallic - 1827 W.C. Zeise

PtCl4 + PtCl2 in ethanol followed by KCl

New Complexes

- 1860-70s = Pt(CO)x complexes

- Mand 1890’s = Ni(CO4) complex

1898-1899

Grignard reagents (RmgX)

- All Grignard reagents are organometallics.

1951 Kealy and Pauson reacted cyclo C5H5mgBr + FeCl3 to try to make _________.

fulvalene

Kealy and Pauson actually made:

Fe(C5H5)2

Strange properties/observations found with new product from Kealy’s and Pauson’s reaction:

1. Very stable (sublimed aka solid to gas without decomposition at 100 degrees Celsius)

2. Resisted hydrogenation (adding H2)

3. Resisted Diels Alder chemistry (combine to form a substituted cyclohexane ring)

1952 - Revised structure of Kealy’s and Pauson’s new compound:

Fe sandwiched between two planar aromatic C5H5^- ligands

- has 10 equivalent Fe-C bonds

- 1956 = structure was confirmed with x-ray

Kealy’s and Pauson’s new compound, Ferrocene has a ______.

coordinate number of 6

- very strange but happens because each Cp- ligand is occupying 3 coordinate sites

Ferrocene was the _______.

start of organometallic chemistry