For Catalysis

Question 1

Which types of d orbitals are often low spin and so are likely to be soft?

Answer 1

4d and 5d

Question 2

What ligands must Ni have to be square planar? What shape is it with the other type?

Answer 2

Strong field ligands, tetrahedral with weak field

Question 3

What field strength is Cl as a ligand?

Answer 3

Weak field = pi-donor

Question 4

What field strength is PPh3 as a ligand?

Answer 4

Weak field

Question 5

What are the isomers for square planar always?

Answer 5

Cis and trans

Question 6

What is a high spin orbital?

Answer 6

Half filled with e-

Question 7

What are the isomers for a metal of 2 ligands with 3 of each?

Answer 7

Fac and mer

Question 8

How is a mer isomer positioned?

Answer 8

180deg between the two ligands furthest away from each other (similar to trans)

Question 9

How is fac isomer positioned?

Answer 9

All of the ligands of the same type are on the same face (similar to cis)

Question 10

What are the isomers for a metal with 2 of one ligand and 4 of another ligand?

Answer 10

Cis and trans

Question 11

What is the en ligand?

Answer 11

BIDENTATE

Question 12

What is the difference between enantiomers and isomers?

Answer 12

Enantiomers = optical with the different shaped bonds
Isomers = position of atoms

Question 13

Eq for metal oxidation state?

Answer 13

Overall charge on the complex - total formal charge on the ligands

Question 14

What makes a ligand soft?

Answer 14

Large ionic radii as they’re further down the periodic table and less electronegative

Question 15

What makes a ligand hard?

Answer 15

Very electronegative and 3d

Question 16

Are hard-soft or hard-hard/soft-soft interactions favoured?

Answer 16

Two of the same

Question 17

When are e- paired vs promoted?

Answer 17

Paired = large deltaOct
Promoted = small deltaOct

Question 18

What makes deltaOct small?

Answer 18

Weak field ligands

Question 19

What makes deltaOct big?

Answer 19

Strong field ligands

Question 20

What is the orbital distortion for d1?

Answer 20

dxy and dx^2-y^2 move down in energy and the electron goes in dxy

Compression

Question 21

What is the orbital distortion for d3?

Answer 21

No distortion bc all 3e- are at the same energy level anyway

Question 22

What is the distortion for high spin d5?

Answer 22

No distortion bc high spin so all orbitals are half filled

Question 23

What is the distortion for low spin d7?

Answer 23

Compression

dz^2 and dx^2-y^2 go down,

Question 24

What is the distortion for high spin d7?

Answer 24

Elongation

dz^2 goes down and dxy goes up

Question 25

What field type is H2O ligand?

Answer 25

Weak field

Question 26

What is the distortion for d8?

Answer 26

No distortion bc pairing so e- paired at the bottom

Question 27

What colour is high spin d5 and why?

Answer 27

Colourless bc all d-orbitals are filled with an unpaired e- Colour is disallowed if the spin of an e- would need to be changed upon promotion

Question 28

When is a complex diamagnetic?

Answer 28

All e- are paired - the spins cancel out so no magnetism

Question 29

What colour is d0?

Answer 29

Colourless bc no e- to promote and so no d<->d transitions

Question 30

What makes something paramagnetic?

Answer 30

Unpaired e- so complex has colour bc d<->d transition can occur upon promotion

Question 31

What makes something high spin?

Answer 31

Weak field ligand

Question 32

What shape does d3 favour?

Answer 32

Octahedral

Question 33

What arrangement are Pd(II) complexes nearly always?

Answer 33

Square planar

Question 34

What gives something a higher pKa?

Answer 34

1) More neutral ligands (e.g. CO) to stabilise the negative charge when a proton leaves and the most stable conjugate base gives a stronger acid 2) A more protic/electronegative metal so the proton is removed more readily 3) If the COMPLEX is negatively charged as it will be unfavourable for it to become more negatively charged by removal of a proton, so the eqm will lie towards this species (acidic)

Question 35

Why do tetrahedral Ni complexes appear blue?

Answer 35

Bc deltaTet is small so the adsorption bands are in the red region of the UV spectrum

Question 36

Are there any isomers for MA2B2 complexes?

Answer 36

No

Question 37

What does a large deltaOct mean?

Answer 37

Small p = paired e- (low spin)

Question 38

What does small deltaOct mean?

Answer 38

P is big so high spin (promoted e-)

Question 39

What is elongation?

Answer 39

z components to down in energy x and y components go up in energy

Question 40

What is compression?

Answer 40

z components go up in energy x and y components go down in energy

Question 41

spin only formula

Answer 41

S = ¬n(n+2) where n = no. of unpaired e- S = total unpaired e- spin

Question 42

what are reduction and oxidation in terms of e-

Answer 42

reduction = addition of e- oxidation = removal of e-

Question 43

how do pi donors and acceptors affect the value for deltaOct?

Answer 43

pi acceptor = increases deltaOct pi donor = decreases deltaOCt

Question 44

how do hard/soft ligands affect deltaOct?

Answer 44

hard = increases deltaOct soft = decreases deltaOCt

Question 45

why are d4, high spin d6, and d9 complexes dissociative?

Answer 45

bc they have longer axial bonds which means that the ligands in the dissociative positions dissociate/ are more readily displaced

Question 46

what mechanism is given by negative entropy (S)?

Answer 46

associative