Difference Between Associative and Dissociative Mechanism

The key difference between associative and dissociative mechanism is that the associative mechanisms are characterized by the binding of the attacking nucleophile to give a discrete and detectable intermediate followed by the loss of another ligand whereas the dissociative mechanisms are characterized by a rate- ...

1. What is associative and dissociative energy?
2. What is ligand dissociation?
3. What is ligand substitution reaction?
4. Is dissociation a defense mechanism?
5. What is trance effect?
6. What is reductive elimination reaction?
7. What do you mean by oxidative addition reaction?
8. Why can electrons usually transition between orbitals in metal complexes?
9. Why ammonia is stronger ligand than water?
10. Can f act as a ligand?
11. Why does ammonia replace water as a ligand?

What is associative and dissociative energy?

Associative substitution describes a pathway by which compounds interchange ligands. The terminology is typically applied to coordination and organometallic complexes, but resembles the Sn2 mechanism in organic chemistry. The opposite pathway is dissociative substitution, being analogous to the Sn1 pathway.

What is ligand dissociation?

The ligand donates an electron pair to the metal and the two molecules come together to form a new bond. Dissociation, in this case, refers to the release of a ligand from a metal. The metal-ligand bond breaks and the ligand leaves with its electron pair. ... The old ligand leaves and then the new one binds.

What is ligand substitution reaction?

Ligand substitution is the first reaction one typically encounters in an organometallic chemistry course. In general, ligand substitution involves the exchange of one ligand for another, with no change in oxidation state at the metal center. ... Charge is conserved in ligand substitution reactions.

Is dissociation a defense mechanism?

Both subjective dissociation states may result from trauma, so dissociation may be considered a psychological mechanisms of defence. This dissociation means the person is emotionally withdrawn from their healthy sense of self and the world, and this cannot protect against future trauma.

What is trance effect?

In inorganic chemistry, the trans effect is the labilization (making more reactive) of ligands that are trans to certain other ligands, which can thus be regarded as trans-directing ligands. ... The discovery of the trans effect is attributed to Ilya Ilich Chernyaev, who recognized it and gave it a name in 1926.

What is reductive elimination reaction?

Reductive elimination is an elementary step in organometallic chemistry in which the oxidation state of the metal center decreases while forming a new covalent bond between two ligands. It is the microscopic reverse of oxidative addition, and is often the product-forming step in many catalytic processes.

What do you mean by oxidative addition reaction?

Oxidative addition is a process that increases both the oxidation state and coordination number of a metal centre. Oxidative addition is often a step in catalytic cycles, in conjunction with its reverse reaction, reductive elimination.

Why can electrons usually transition between orbitals in metal complexes?

The d-orbitals are the frontier orbitals (the HOMO and LUMO) of transition metal complexes. ... Because transition metals are generally less electronegative than the atoms on the ligands (C, N, O, Cl, P...) that form the metal-ligand bond, our convention is to assign both electrons in the bond to the ligand.

Why ammonia is stronger ligand than water?

NH3 is a ligand with medium field strength. ... In case of H2O, it is weaker ligand as compared to NH3 as the donor atom is Oxygen which is more electronegative than Nitrogen. So as the electronegativity of central atom decrease, the ligand becomes stronger.

Can f act as a ligand?

Examples of electrically charged monodentate ligands are halide ions, such as: F^-, Cl^-, Br^-, I^-, and cyano, CN^-. The overall charge on a complex is the arithmetic sum of the oxidation state of the metal in the center plus the charge(s) brought to the complex by each ligand.

Why does ammonia replace water as a ligand?

Replacing water molecules by ammonia

Water molecules and ammonia molecules are very similar in size, and so there is no change in co-ordination this time. ... Ammonia solution can react with hexaaqua metal ions in two quite distinct ways, because it can act as a base as well as a ligand.