Molecular Orbital Theory and Coordination Compounds

Dr. Anit Pooji introduces the concept of bonding in coordination compounds, focusing on molecular orbital theory applied to octahedral complexes. The video explains the molecular orbital diagrams for sigma bonding, using examples of titanium, iron cyanide, and iron chloride complexes. It highlights the differences in electron pairing and magnetic properties based on ligand strength. The video concludes with practice problems for viewers to solve.

What is the main focus of the lecture on coordination compounds?

• The bonding in coordination compounds

• The structure of organic compounds

• The physical properties of metals

• The synthesis of coordination compounds

In the molecular orbital diagram for octahedral complexes, what do t2g orbitals represent?

• Singly degenerate orbitals

• Triply degenerate orbitals

• Doubly degenerate orbitals

• Non-degenerate orbitals

What is the oxidation state of titanium in the titanium hexaaqua complex?

• +1

• +2

• +3

• +4

How many unpaired electrons are present in the titanium hexaaqua complex?

• Three

• Two

• One

• None

What is the nature of the iron hexacyanide complex in terms of magnetism?

• Diamagnetic

• Antiferromagnetic

• Ferromagnetic

• Paramagnetic

Why is the gap between t2g and eg orbitals larger in the iron hexacyanide complex?

• Because iron is in a high oxidation state

• Because iron is in a low oxidation state

• Because cyanide is a strong ligand

• Because cyanide is a weak ligand

What is the electronic configuration of Fe in the iron hexacyanide complex?

• 3d6

• 3d5

• 3d7

• 3d8

In the context of molecular orbital theory, what happens when a ligand is weak?

• Electrons pair up in the eg orbitals

• Electrons pair up in the t2g orbitals

• Electrons remain unpaired in the eg orbitals

• Electrons remain unpaired in the t2g orbitals

Which of the following is a characteristic of a strong ligand?

• It causes a large gap between t2g and eg orbitals

• It does not affect the gap between t2g and eg orbitals

• It causes electrons to remain unpaired

• It causes a small gap between t2g and eg orbitals

What is the effect of a weak ligand on the magnetic properties of a complex?

• It makes the complex strongly paramagnetic

• It makes the complex weakly paramagnetic

• It has no effect on the magnetic properties

• It makes the complex diamagnetic