M2 Lecture 11/12/13

Question 1

Highly colored ions have…
a) full/empty d-orbitals
b) partially filled d-orbitals

Answer 1

b) partially filled d-orbitals

Question 2

If we observe transitions b/w d-orbitals:
a) no color
b) see color
c) degenerate
d) d-orbs are no longer degenerate

Answer 2

b and d / see color and d-orbs are no longer degenerate

Question 3

Which one of the following is colorless?
a) Co2+
b) Cu2+
c) Zn2+

Answer 3

c) Zn2+

Question 4

lobes

Answer 4

regions of of an orbital with high probability of electrons being there

Question 5

node

Answer 5

region of the probability of electrons present is equal to 0 - wavefunction will change sign

Question 6

Octahedral Geometry Ligands (CN=6, delta o)

Answer 6

having direct overlap with the lobes with result in higher energy (dz^2, dx^2y^2)

having indirect overlap with the lobes will result in lower energy (dxy, dxz, dyz)

Question 7

Octahedral Geometry Ligands (CN=6, delta o)

Answer 7

– (dz^2, dx^2y^2)
— (dxy, dxz, dyz)

Question 8

How to check for coordination isomers?

Answer 8

2 complexes with different center metals

Question 9

How to check for ionization isomers

Answer 9

Look for counter ion outside the [brackets] that could become a ligand

Question 10

How to check for linkage isomers?

Answer 10

Monodentate ligands with multiple bonding sites (lone pairs)
-can look at spectrochem series for underlined atoms
-evaluation of formal charge

Question 11

How to look for geometric isomers

Answer 11

-check for 2 ligands of the same type (cis/trans possible for square planar and octahedral)
-check for 3 ligands of the same type (fac/mer possible for octahedral)

Question 12

How to check for optical isomers?

Answer 12

Draw and evaluate chirality by looking for mirror plane (which is not chiral)
-can not be superimposed
if tetrahedral geometry and all 4 ligands are different, it is chiral

Question 13

According to the Crystal Field Theory (CFT), ligands are viewed as a point of (negative/positive) charge.

Answer 13

negative

Question 14

According to the Crystal Field Theory (CFT), metal cations are viewed as a point of (negative/positive) charge.

Answer 14

positive

Question 15

T/F All TM have the same 5 orbitals (dxy, dyz, dxz, dz^2, and dx^2y^2)

Answer 15

True

Question 16

Will electrons on the transition metals attract or repel the electrons on the ligands?

Answer 16

Repel

Question 17

Will more overlap of the transition metal eletrons and ligand electrons increase or decrease energy?

Answer 17

Increase energy
More overlap = more repulsion - higher energy

Question 18

Will an octahedral complex have a larger delta o if the ground level states are paired up first or if the upper levels are populated first?

Answer 18

It will have a larger delta O if the ground levels are paired up first. This is because the paired levels have a spin of 0.

So you would have
+1/2 _ +1/2 +1/2
0 0 0 vs 0 0 +1/2
+1/2 less than +3/2, lower spin = larger splitting energy

Question 19

How to assign ms (spin) to an orbital?
-filled orbital vs unfilled orbital

Answer 19

filled orbital = 0 spin
unfilled orbital (one electron = +1/2 spin

Question 20

What does the ms (spin) number relate to?

Answer 20

The number of unpaired e-

Question 21

How are ligands arranged on the spectrochemical series?

Answer 21

strongest field ligands to weakest field ligands with H2O being in the center (still relatively weak)
or
largest delta o to smallest delta o

Question 22

If a ligand is (strong/weak) according to the spectrochemical series, this means that the complex will have a (larger/smaller) splitting energy aka delta o.

Answer 22

strong - larger
weak - smaller

Question 23

If a strong ligand is in a complex, will you pair the electrons first or popuate the highest levels first?

Answer 23

Pair e- first
If it is strong, that means that it has a larger delta o, which means it has a lower spin. If it has a lower spin, there should be less unpaired e-.

Question 24

If a weak ligand is in a complex, will you pair the electrons first or popuate the highest levels first?

Answer 24

Populate higher levels first
If it is weak, that means that it has a smaller delta o, which means it has a higher spin. If it has a higher spin, there should be more unpaired e-.

Question 25

If the colors of 2 complexes are given, how would you assign the colors to each complex?

Answer 25

1. For each complex, identify if the ligand is strong/weak. -the stronger ligand will absorb less nm (MORE ENERGY). the weaker ligand will absorb more nm (LESS ENERGY) 2. On the color wheel, identify the colors that are appeared and absorbed. The numbers that we care about is the wavelength of the color that is ABSORBED. 3. Compare the wavelength (nm) of both colors that are absorbed. Recall that a smaller wavelength will have more energy. 4. Smaller wavelength = stronger ligand // greater wavelength = weaker ligand.

Question 26

If green is absorbed, what color would it emit?

Answer 26

Red

Question 27

[Fe(CN)6]4- is yellow. What colors are possible for [FeCl6]4-? Assume not yellow

Answer 27

Because Cl- is a weaker ligand than CN-, Cl- will absorb colors that are lower in energy than the color that CN- absorbed. Violet is absorbed by CN-. Colors that are lower in energy than violet and greater than yellow is green and blue.

Question 28

What has a higher energy: blue or orange?

Answer 28

Blue The longer your wavelength, the less energy you have. Because blue has a shorter wavelength, it has higher energy than orange.

Question 29

For tetrahedral complexes, all ligands are (on/off) axes, thus highest energy aka most overlap will be (on/off) axes.

Answer 29

Off;off

Question 30

Will a tetrahedral complex have a larger delta o if the ground level states are paired up first or if the upper levels are populated first?

Answer 30

It will have a larger delta T if the upper levels are populated first. This is because there is more overlap with off axes.

Question 31

Delta T is always (low/high/0) spins.

Answer 31

high

Question 32

What is larger, delta T or delta O?

Answer 32

Delta O because tetrahedral electrons have less overlap with orbitals so they are lower in energy.

Question 33

Tetrahedral Geometry Ligands (CN=4, delta t) How are the orbitals lined up on the diagram?

Answer 33

--- (dxy, dxz, dyz) -- (dz^2, dx^2y^2)

Question 35

Square Planar Geometry Ligands (CN=4, delta sp) How are the orbitals lined up on the diagram?

Answer 35

- (dx^2y^2) - (dxy) - (dz^2) -- (dxz, dyz) (how to remember: less overlap with z orbs)

Question 36

The higher the orbital on the energy level diagram, the (less/more) overlap, (lower/higher) energy.

Answer 36

more overlap, higher energy

Question 37

Linear Geometry Ligands (CN = 2, delta l) How are the orbitals lined up on the diagram?

Answer 37

- (dz^2) -- (dxz, dyz) -- (dxy, dx^2y^2) (how to remember: more overlap with z orbs)

Question 38

[Ni(CN)4]2- is diamagnetic. Is it tetrahedral or square planar?

Answer 38

Diamagnetic = no unpaired e- config of Ni2+ = [ar] 3d^8 1! 1_ 1_ __ 1! 1! 1! 1! 1! 1! Square planar!

Question 39

Which geometry is most common? -linear -square planar -tetrahedral -octahedral

Answer 39

octahedral