1. Organometallic Chemistry. 1
What are organometallic compounds?
What do organometallic compounds do?
What organometallic chemistry will you do?
Organometallic compounds have M-C bonds
In reality, other M compounds without M-C bonds are considered “organometallic” if they can form M-C bonds
Image credits

2. Organometallic Chemistry. 1
What are organometallic compounds?
What organometallic chemistry will you do?
What do organometallic compounds do?
Ru3(CO)12
What the
happened here???
Grubb’s catalyst,
famous for olefin metathesis
RuCl2Pcy3(=CHPh)
Ru2(cot)(CO)6
To see more:

3. Organometallic Chemistry. 1
What do organometallic compounds do?
What are organometallic compounds?
What organometallic chemistry will you do?
Use some important ligands
Do some key reaction types
Learn some fundamental concepts

4. Organometallic Chemistry. Ligands
Prototypical
Carbon Monoxide, CO
Carbonyl ligands
Why prototypical
Metal carbonyls are frequent starting materials
Metal carbonyls are known for most transition metals
Metal carbonyls are reactive — labile — CO is easily substituted
CO lost as gas is swept from system, pushes reaction forward
Metal carbonyls are easily studied by IR and provide information
on structure, symmetry, electron density changes at metal

5. Organometallic Chemistry. Metal Carbonyls
Metal carbonyls are known for most transition metals
Fe(CO)5
Fe2(CO)9
Fe3(CO)12
Co4(CO)12
Mo(CO)6
Ni(CO)4
To see more:

6. Organometallic Chemistry. Metal Carbonyls
Metal carbonyls clusters are big!
[Rh12(m12-Sn)(CO)27]4-
one-step synthesis of [Pt38(CO)44]2- dianion from [PtCl6]2- potassium salt.

7. Organometallic Chemistry. Metal Carbonyls
Metal carbonyls as vitamins??!!!
COMPOSITION PER CAPSULE :
Iron (as iron carbonyl USP) mg
Vitamin B9 (Folic acid BP) ,5mg
Vitamin B12 (Cyanocobalamine USP) µg
Vitamin C (Ascorbic acid USP) mg
Zinc (as sulfate BP) ,5mg
Excipients for one capsule.
EXCIPIENTS WITH KNOWN EFFECT :
None.
PROPERTIES :
Antianemic preparation with iron and folic acid.
This association with Vitamin B12 and Zinc participate
in the haemoglobin synthesis process.
Ferronyl (iron carbonyl)
Also:

8. Organometallic Chemistry. Metal Carbonyls
Bonding in Metal carbonyls understood with MOT
pi bonding =
donation from M to LUMO on C
sigma bonding =
donation from HOMO on C C
atomic
orbitals O
atomic
orbitals CO
molecular
orbitals

9. Organometallic Chemistry. Concepts.1
Predicting structure
18 electron Rule or Effective Atomic Number (EAN) Rule
“a stable organometallic compound has 18 valence electrons at the metal”
Examples

11. Organometallic Chemistry. Concepts.1
Predicting structure
18 electron Rule or Effective Atomic Number (EAN) Rule
“a stable organometallic compound has 18 valence electrons at the metal”
Examples
Ni(CO)4
And so for Ni0??

12. Organometallic Chemistry. Concepts.1
18 electron Rule or Effective Atomic Number (EAN) Rule
Mo(CO)5(PPh3)
Meet some new ligands
:PPh3
:PR3
MeCN, thf, MeOH (donor solvents)
“diphos” or “dppe” = Ph2P:(CH2)2P:Ph2
:X-, :Cl-, :Br-, :OH-, :SR-

13. Organometallic Chemistry. Concepts.1
18 electron Rule or Effective Atomic Number (EAN) Rule
Can you think of other possible ligands for organometallics?

14. Organometallic Chemistry. Reactions.1
Ligand Subsitution
Metal carbonyls are frequent starting materials because
metal carbonyls are reactive — labile — CO is easily substituted
Mo(CO)6 + energy  “Mo(CO)5” + CO(g)
Mo(CO)5 + L  Mo(CO)5L
Predicting reactivity: use Concept 1.
18 electron Rule or Effective Atomic Number (EAN) Rule
“a stable organometallic compound has 18 valence electrons at the metal”

15. Organometallic Chemistry. Reactions.1
Carbonyl Substitution can be Thermal or Photolytic
Mo(CO)6 + hnenergy  “Mo(CO)5” + CO(g)
Photolysis excites one electron to an antibonding orbital, and one M-C bond is broken
monosubstituted Mo(CO)5 + L  Mo(CO)5L
Mo(CO)6 + heat energy  “Mo(CO)3” CO(g)
Thermolosis adds enough energy to break several M-C, and causes molecule to lose as many CO’s as is favorable
trisubstituted Mo(CO) L  Mo(CO)3L3

16. Organometallic Chemistry. Reactions.2
Oxidative Addition
Recognized by two characteristics:
increase of M oxidation state, Mn+  M(n+2)+
increase in number of coordinated atoms— coordination number, CN
Fe(CO)5 + Cl2  Fe(CO)4Cl2 + CO(g)
Fe0(CO)5 + Cl2  Fe2+(CO)4Cl2 + CO(g)
CN = CN = 6

17. Organometallic Chemistry. Reactions.2
Oxidative Addition
Does it obey the 18 e- Rule?
Fe0(CO)5 + Cl2  Fe2+(CO)4Cl2 + CO(g)

18. Organometallic Chemistry. Do it!!
This week’s reactions
Reaction A: Mo0(CO)6 + diphos  ? n CO(g)
Reaction B: product of A + I2  ? n’ CO(g)
What do these reactions make? How can we tell? Ideas?

19. Organometallic Chemistry. Do it!!
This week’s reactions
Reaction A: Mo0(CO)6 + diphos  ? n CO(g)
Reaction B: product of A + I2  ? n’ CO(g)
Reaction Conditions
(1) anaerobic reaction—WHY?—How?
(2) Rxn A is heated—why?

20. Organometallic Chemistry. Do it!!
Prep for this week’s reactions
Reaction A: Mo0(CO)6 + diphos  ? n CO(g)
Reaction B: product of A + I2  ? n’ CO(g)
Preparation
(1) clean and dry necked flask.
(2) clean and dry stir bar
(3) anaerobic set-up: what do you know?
(4) use heating mantle
(5) ppt with hexanes
(6) filter with Hirsch funnel (what’s that?)