This document discusses organometallic compounds and their uses as catalysts in homogeneous and heterogeneous reactions. It provides examples of homogeneous catalysis using organometallic compounds like cobalt carbonyl and rhodium complexes. The mechanisms involve steps like oxidative addition, CO insertion, 1,2-insertion, and reductive elimination. Examples of heterogeneous catalysis on titanium surfaces are also provided. Finally, the document lists references used.

1. Presented by:
Biswajit Moran
M. Sc. 4th semester
Chemistry Department

2. (1) Introduction
(2) Some Examples and Their Mechanism
(3) Uses
(4) References
(5) Acknowledgement

3. (1) Compound containing metal-carbon bonds are the
Organometallic compounds.
(2) Organometallic chemistry contain both σ- and π-bonds
between metal and the C-atom.
(3) First discovery was Ziese’s salt,
(4) Organometallic catalyst and Organometallic catalysis.

4. A) HOMOGENEOUS CATALYSIS:
CH2R2C + CO + H2 R2CH
H2
C C H
O
HCo(CO)4
HCo(CO)3
HCo(CO)3
R2C CH2
(1)
(2)
(18 Electrons)
- CO ; Dissociation of CO, inhibited by excess CO
(16 electrons)
+ ; Coordination of olefin
(18 electron)
R2C CH2
HCo(CO)4
High pressure

5. R2C
H2
C Co(CO)3
H
R2C
H2
C Co(CO)4
H
R2C
H2
C C
H
Co(CO)3
O
(3)
(4)
(5)
(6)
1,2-insertion
(16 electrons)
+ CO ; addition of CO
(18 electrons)
alkyl migration
(16 electrons)
+ H2 ; Addition of H2(oxidative addition)

6. R2C
H2
C C
H
Co(CO)3
O H
H
R2C
H2
C C
H
H
O
+ HCo(CO)3
(7)
(18 Electrons)
Reductive elimination

7. CH3OH + CO
Rh Catalyst
HI
CH3COOH
(16 electron)
(18 electron)
(2)
(3)(4)
(5)
Oxidative addition;
rate determining step
CO insertion=
alkyl migration
(16 electron)
Co-ordination of CO
Reduction
elimination
(18 electron)
(1) CH3OH + HI CH3I + H2O

8. H2C CH2
[PdCl4]2-
H2O
H3C C
O
H
Pd
Cl
Cl
Cl
Cl
Pd
Cl
Cl
Cl
CH2
H2C
+ Cl-
H2C CH2

9. Pd
H2O Cl
Cl
CH2
H2C
+ Cl-
Pd
OH2 Cl
Cl CH2CH2OH
+ H+
+ H2O
H2O:

10. Details: Pd
Cl OH2
Cl
HO:
H
C
H2
H
H3C C
OH
H
+ Pd[0]
+ 2Cl- + H2O
H3C C
OH
H + Pd[0] + 2Cl-
Catalyst
regenerated
by reaction
with CuCl2
H3C C
O
H + H+

11. + H2
ClRh(PPh3)
H C C C
H H
H H
H
H
H
(Oxidative addition)
(Ligand dissociation)
(Co-ordination of olefin)
(1,2-insertation,
Rate determining
step)
Reduction
elimination

12. B) HETEROGENEOUS CATALYSIS:
Ti CH2R H2C CH2
H2C CH2
Ti CH2R
1,2- insertion
Ti CH2CH2CH2R
Ti(CH2CH2)nCH2R

13. 1) Conversion of simple molecules into more complex
molecules
~ ethylene into acetaldehyde,
~ methanol into acetic acid,
~ organic monomers into polymers.
2) Conversion of one molecule into another same type
molecule, eg- one alkene into another.
3) Selective reaction at a particular molecular site
~ replacement of Hydrogen by Deuterium ,
~ selective hydrogenation of a specific double bond

14. 1) INORGANIC CHEMISTRY(Third edition)
-Gary L. Miessler & Donald A. Tarr
2) INORGANIC CHEMISTRY-Principal , Structure & Reactivity(4th Edition)
- James E. Huheey, Keiter & Keiter
3) INTERNET SOURCES