d-d spliting

Question 1

Along xy, yz and xz plane?

Answer 1

Lobes oforbitals lie in between axes

->repulsion bt lp of e of ligands and 3d e in these orbitals is lesser

Question 2

xy plane and z axis?

Answer 2

e in d-orbitals are pointing towards lp of e of the ligands;

Repulsion bt lp e of ligands and 3d e in these orbitals is more

Question 3

Main determining factor for d-d splitting

Answer 3

Presence of ligands not light!!!

Question 4

Two criteria for complexes to be Colour

Answer 4

1. Splitting of d orbital

2. Partially filled 3d subshell

Question 5

When answering questions on Colour?

Answer 5

1. Splitting of 3d orbitals in the presence of ligands;
2. Promotion of e from lower energy orbitals to higher energy;

Partially filled d orbital;

3. Colour seen

Question 6

Why TM often colored

Answer 6

Presence of ligands, 3d orbitals of TM are split into two groups of metals with small energy diff;

Diff in energy bt orbitals fall within the energy (wavelength) range of visible light;

In complexes where 3D orbitals partially filled;
Exposed to light, e in lower energy level of 3d orbitals promoted to those in higher energy level by selective absorption of light in the visible range;

Colour seen is complement of those absorbed in visible range of spectrum