Biocoordination Chemistry 2

Question 1

Crystal Field Theory

Answer 1

a theory that describes bonding in transition metal complexes

Question 2

Ligands are regarded as point

Answer 2

negative charges

Question 3

Axial d orbitals have lobes along the

Answer 3

the x, y and z axes

Question 4

Inter-axial d orbitals have lobes

Answer 4

between the x, y and z axes

Question 5

Imagine the ligands approaching the metal d orbitals in an octahedral field
+/- attraction
-/- repulsion

This -/- repulsion will be greater between the ligand electrons and electrons in ___________ as compared to repulsion between the ligand electrons and those in the _____________

Answer 5

axial d orbitals, d inter-axial orbitals

Question 6

The extent of d orbital splitting depends on

Answer 6

the metal ion, the charge on the metal ion and the ligands coordinated

Question 7

Metal: Larger metal —–>

Answer 7

Larger splitting

Question 8

Higher Oxidation State —–>

Answer 8

Larger splitting

Question 9

List the Ligand: Spectrochemical series

Answer 9

Cl- < F- < H2O < NH3 < en < NO2- < (N-bonded) < CN-< CO

Question 10

Weak Field Ligand

Answer 10

Low electrostatic interaction: small splitting

Question 11

High Field Ligand

Answer 11

High electrostatic interaction: large splitting

Question 12

If low splitting, then electrons can fill inter-axial and axial orbitals singly before pairing

Answer 12

High Spin Complexes

Question 13

If large splitting, then electrons will completely fill inter-axial orbitals first – low spin complexes

Answer 13

Low Spin Complexes

Question 14

What’s the difference between paramagnetic and diamagnetic?

Answer 14

Paramagnetic materials have unpaired electrons and are weakly attracted to magnetic fields, while diamagnetic materials have all electrons paired up and are weakly repelled by magnetic fields.