topic 5 Flashcards
octahedral disturbance in degeneracy levels
t2g
eg
between t2g and eg, what has the lower energy one
t2g
what gets filled first t2g or eg
t2g
bc of the aufbau principle
random electron config using t2g and eg
put the number of electrons as powers for each of the splits
what is the max number of electrons that can occupy the t2g
6 electrons
what is the max number of electrons that can occupy the eg
4
what is the total max number of electrons for t2g and eg
10 electrons
bc it’s the d block
what is CFSE
crystal field stabilising energy
🔺o
is t2g stabilising or destabilising
stabilising
is eg stabilising or destabilising
destabilising
what value does adding an e- to the t2g add to 🔺o
adds (-0.4)
bc it’s -2/5
what does adding an e- to eg do to the 🔺o value
adds -0.6 as its + 3/5
what is the 🔺o if:
t2g^1 eg^0
-0.4 CFSE
what configurations have 2 possible spin states
d4
d5
d6
d7
what are the 2 possible spin states
high spin
low spin
what is a high spin config
max number of unpaired e-
the e- enters the high energy split (eg)
P >🔺o
what is low spin config
min number of unpaired e-
e- are paired up in lower split (t2g)
P < 🔺o
what does a higher 🔺o mean
a higher CFSE
MEANS ITS A LOW SPIN CONFIG
what is 🔺o tensioned against
it’s tensioned against Pairing Energy
what must we do when calculating CFSE for low spin
we need to add the pairing energy
(this depends on the number of unpaired e-)
does changing ligands change the 🔺o (cm-1)
YES!!
what does a more negative cm-1 value mean
it’s more stabilised
it’s high spin
(majority of e- are unpaired)
what is diff between octahedral and tetrahedral shapes
in octahedral there’s high and low spins
in TETRAHEDRAL there’s only HIGH SPIN - follow aufbau principle and don’t pair up
how do TM ions have magnetic properties
bc they have unpaired e- resulting in diff types of magnetism
what are the diff types of magnetism
- diamagnetism
- paramagnetism
- ferromagnetism
what is diamagnetism
very weak effect associated with paired e-
all compounds some amounts of this
what is paramagnetism
weak effect due to the presence of unpaired electrons
what is ferromagnetism
a strong effect
example of a bulk magnetic property that results from long range electron electron interactions
what is the equation for the spin magnetic moment ( u s.o)
u s.o = root N(N+2) uB
N is the number of unpaired e- in the non d generate configuration
what is uB in the spin only magnetic moment ( u s.o)
this is the units for the spin only magnetic moment
u s.o
what is the spin only magnetic moment for high spin for d4
4.9uB
what is the spin only magnetic moment for low spin d4
2.83 uB
what is a strong field ligand
ligands with a large 🔺o
what is a weak field ligand
ligands with small o🔺
what spin configuration do strong field ligands promote
low spin configurations
aka think of it as the energy CFSE 🔺o is too large to put e- in the eg orbitals so they must be low spin
what spin configuration do weak field ligands promote
they promote high spin configurations
how do we remember if smt is high spin or low spin
p > 🔺o
plane in the sky is high
means high spin
p<🔺o
means low spin
how do we figure out if a complex is high spin or low spin
find the CFSE
( x -2/5. and x 3/5)
multiply this by the 🔺o
for paired up e- (low spin config) add the pairing constant
the more (-) number is the spin it is!!!!
