Transition Metals & Coordination Chemistry

These flashcards cover key concepts related to transition metals and coordination chemistry, focusing on molecular orbital theory applied to different ligand types.

What is the key objective when analyzing octahedral ML6 complexes with ligands?

To apply LGO approach and determine the complete MO diagram for complexes with π-donor and π-acceptor ligands.

What are the two types of ligands considered in the bonding of octahedral complexes?

π-donor ligands and π-acceptor ligands.

How do π-donor ligands interact with metal orbitals in octahedral complexes?

They donate electrons from a filled orbital to empty metal orbitals through σ-donation and π-donation.

In MO diagrams for octahedral TM complexes with π-donor ligands, what happens to t2g and eg orbitals?

t2g orbitals have bonding interactions, while eg orbitals are non-bonding.

What is the impact of π-donation on the MO diagram compared to pure σ-donor complexes?

There is a change in the middle of the MO diagram due to the addition of π-donation contributions.

What distinguishes π-acceptor ligands from π-donor ligands in coordination complexes?

π-acceptor ligands allow electrons to flow from the metal to the vacant π* orbital of the ligand.

How does the MO diagram change for complexes with π-acceptor ligands compared to π-donor ligands?

The anti-bonding t2g* MOs are more destabilized, resulting in increased Δo and favoring low spin configurations.

What does Δo represent in molecular orbital theory?

The energy difference between bonding and anti-bonding molecular orbitals.

What is the trend of Δo with respect to ligand type?

Δo increases in the order: π-donor < σ-donor < π-acceptor.

How does the presence of 6 π-acceptor ligands affect the stability and electron configuration of TM complexes?

They contribute 12 σ electrons and increase the energy level of t2g* orbitals, making low oxidation state TM complexes more stable.