Electronic States Flashcards
The interaction that mixes a ground state into a particular excited state must transform as the_______.
Direct product of the symmetry of the two states.
Γgs ⊗ Γex
(First step in determining if spin-orbit coupling mixes an excited state into an ground state.)
Relaxation of an excited state to a ground state that emits a photon without a change in spin multiplicity.
Fluorescence
This process occurs when an excited molecule or atom relaxes to a lower energy state (possibly the ground state) through emission of a photon.
Luminescence
Relaxation of an excited state to a ground state that emits a photon with a change in spin multiplicity.
Phosphorescence
A process where there is a conversion between electronic states of different multiplicity.
Intersystem Crossing
In order that the spin-coupling operator mix a ground state into a particular excited state, what is required?
- The energy difference between the two states must be small
- The direct product of the two states must contain the irreducible representation of the spin-coupling operator.
A phenomenon that arises in paramagnetic systems with multiple unpaired electrons (i.e., S > 1/2) as a result of both spin–spin coupling (SSC) and spin–orbit coupling (SOC) interactions
Zero-field splitting
The spin-orbit coupling operator directly splits the degeneracy of a group state without resorting to a distortion.
In-state orbital angular momentum
When the spin-orbit coupling operator cannot split degeneracy of a state and requires coupling to a low lying excited state and a molecular distortion.
Out-of state orbital angular momentum
The interaction between electronic and nuclear vibrational motion that leads to d-d transition becoming more Laporte allowed
Vibronic Coupling
A type of electronic transition that involves a transition from metal dominated MOs in the ground state to ligand dominated MOs in the excited state.
Metal-Ligand Charge Transfer
A type of electronic transition between two metal sites differing only in oxidation state
Intervalence charge transfer
A type of electronic transition that involves a transition from ligand dominated MOs in the ground state to metal dominated MOs in the excited state
Ligand-Metal Charge Transfer

What non-radiative exchange mechanism is shown below?
Triplet-Triplet Dexter Energy Transfer


What non-radiative exchange mechanism is shown below?
Singlet-Singlet Dexter Energy Transfer


What non-radiative exchange mechanism is shown below?
Singlet-Singlet Foster Energy Transfer

The characteristic of f-f transitions in Lanthanide:
- Characteristic wavelengths
- Narrow line widths
- Millisecond lifetimes (Long lifetimes)
- Laporte forbidden
Which electronic transition will have the higher value of epsilon in the d2 metal complex?
4A2g —-> 2Eg
4A2g —-> 4T2g

4A2g —-> 4T2g
4A2g —-> 2Eg is spin forbidden
Electronic transitions between states with different spin multiplicities.
Spin Forbidden
How does the spin-orbit coupling operator transform in a particular point group?
Rx Ry Rz (infinitesimal rotations)
How many microstate does the 3F term symbol contain?
21
—————————————————————–
F —> L=3 —> 2*(3)+1=7
7*3=21
The degeneracy of the |Ms> sublevels of the ground state is lifted in the absent of a magnetic field.
Spin-Orbit Coupling
Ground state will have the _____spin multiplicity.
Largest
If thesame spin multiplicity, then the GS will have the highest value of L.
In Oh and D4h , all d orbitals are gerade and so too are the states arising from their d configurations. Thus, their electronic transitions between them are________.
Laporte Forbidden
If a system is centrosymmetric, electronic transitions between states with the same inversion symmetry (g –> g, u –> u) are forbidden, but transitions between states of different inversion symmetry
(g –> u, u –>g) are allowed.
Laporte’s Rule
Idenifty the gaseous ground state term symbol for a d2 metal ion.

<strong>3</strong>F

Idenifty the strong field region of the
d5 Tanabe-Sugano Diagram.


Low Spin Configurations
Idenifty the weak field region of the
d5 Tanabe-Sugano Diagram.


High Spin Configurations
What is the symbol for the rhombic ZFS component?
E parameter
What is the symbol for the axial ZFS component?
D parameter
Idenifty the states that are involved in an avoided crossing
in the reaction coordinate below.


The a1 states
Non-Crossing Rule
Two states of the same symmetry and spin multiplicity cannot cross. Instead, they will admix in order to cause an avoided crossing.
Determine ML and MS vaules of the free ions term below:
2D
D: L=2 ML={-2,-1,0,1,2}
2S+1=2 –> S=1/2 –> MS= {1/2,-1/2}
BAc
A: Total orbital angular momentum (L)
B: Spin multiplicity (2S+1)
C: Total angular momentum (J)