Organometallic chemistry intro

Question 1

What is an organometallic compound? (DEFINITION)

Answer 1

A compound possessing a direct polar bond between the metal and one or more carbon atoms of an organic fragment, and must have a hydrogen attached

Question 2

What is the role of the metal in organometallic chemistry?

Answer 2

Coordination of the organic fragment can modify its reactivity
Metal can activate bonds and act as a template to facilitate bond formation
The metal can stabilise highly reactive organic molecules

Question 3

What is the composition of an organometallic compound?

Answer 3

Organic fragment
Spectator ligand Ln
Actor ligand X

Question 4

What is the role of the spectator ligand?

Answer 4

Stabilises the metal complex
Controls solubility and stability
Modifies the reactivity of organic entity and controls selectivity and efficiency of the transformation

Question 5

What is the composition of the spectator ligands

Answer 5

Neutral 2e ligand

Question 6

What are the features of the actor ligand?

Answer 6

Can be either Cl, Br, I, OR or H
Reactive
Can be substituted by any incoming reagent

Question 7

What are the features of the organic fragment?

Answer 7

Bonded to the metal (either sigma or sigma/pi)

Reactive/activated

Question 8

There are 4 types of organometallic compounds, what is the first?

Answer 8

Contains a coordinated unreactive organic fragment that acts as a ligand

Question 9

There are 4 types of organometallic compounds, what is the second?

Answer 9

Contains a reactive organic fragment which participates in the reaction and can be isolated

Question 10

There are 4 types of organometallic compounds, what is the third?

Answer 10

Contains both an organic spectator ligand and reactive organic fragments which are generally generated in situ

Question 11

There are 4 types of organometallic compounds, what is the fourth?

Answer 11

The compound is generated in situ from a reactive inorganic coordination compound and a substrate ad is generally not isolated, but is a reactive intermediate

Question 12

What is the involvement of RM complexes in the generation of single enantiomer compounds?

Answer 12

Carries out the catalytic asymmetric hydrogenation of C=C bonds

Question 13

What does the organometallic catalyst do in asymmetric hydrogenation?

Answer 13

Activates the H2
Coordinates the alkene
Forms two C-H bonds
Controls which enantiomer is formed

Question 14

What does the organometallic catalyst do in the catalytic asymmetric isomerisation of C=C bonds?

Answer 14

Assists H migration

Controls the stereochemistry of migration, forms a chiral centre

Question 15

What is the role of organometallic catalysts in the polymer industry?

Answer 15

Carbon-carbon bond formation and controls the stereochemistry

Question 16

What is the role of palladium catalysts in pharmaceuticals?

Answer 16

Forms biaryl based pharmaceutical products

Cleaves the C-Cl and C-B bonds, subsequently forming the C-C bond

Question 17

What is hydroformylation?

Answer 17

A process that adds CO and H2 to an alkene

Question 18

What is the role of the organometallic catalyst in hydroformylation?

Answer 18

Facilitates H-H bond cleavage
Promotes C-CO and C-H bond formation
Controls selectivity (linear product)

Question 19

What are the reasons for using transition metals in RM complexes?

Answer 19

A variety of ligands bind to TM
Variety of oxidation states
TM exhibit several different geometries and coordination number

Question 20

What properties do the ligands control in the RM complex?

Answer 20

Activity
Stability
Selectivity

Question 21

Why is it beneficial to use palladium based catalysts in the synthesis of pharmaceutical products?

Answer 21

Large industrial scale
Fewer steps
Cost effective

Question 22

How do you calculate the d electron count?

Answer 22

Group number - oxidation state