U1-3-3 - Complex Colours and Catalysis Flashcards
In a free transition metal ion the d orbitals are ________.
degenerate
Why are d orbitals split in TM complexes?
The e− present in approaching ligands cause the e− in the orbitals pointing at ligands to be repelled.
This repulsion increases the energies of these orbitals.
What is delta (∆)?
Crystal field splitting energy
(energy gap between split d orbitals)
How are split d orbitals filled?
Lower ones filled in first. After d6, the higher ones are filled.
Electrons can be promoted from __________ energy d orbitals by absorbing light. This is called a d→d transition.
lower to higher
Electrons can be promoted from lower to higher energy d orbitals by _________________. This is called a d→d transition.
absorbing light
Electrons can be promoted from lower to higher energy d orbitals by absorbing light. This is called a _________________.
d→d transition
What is the spectrochemical series?
List of ligands in order of their ability to split d orbitals.
State a general principle to how the ligands are ordered.
Ligands containing N split the d orbitals the most.
Ligands containing O are in the middle.
Halides split the d orbitals the least.
If a complex is colourless, it absorbs _________.
UV light
Suggest two reasons a complex could be colourless (in terms of electrons/orbitals).
No d → d transitions possible (e.g. d10)
Crystal field splitting energy is large (wavelength absorbed in UV and not visible spectrum)
The complex colour is ___________ to the colour absorbed (opposite on colour wheel).
complementary
The complex colour is complementary to the colour absorbed (___________ on colour wheel).
opposite
Homogenous catalyst
Catalyst in the same state as the reactants
Heterogenous catalyst
Catalyst in a different state to the reactants
