topic 3

Question 1

how many valence orbitals does a TM have

Answer 1

9!!
1 s
3 p
5 d

Question 2

if there are 9 atomic orbitals it means there are

Answer 2

9 molecular orbitals
they maximise bonding when all filled

Question 3

compounds with 18e- are said to be

Answer 3

coordinatively saturated or electron precise

stable

Question 4

why is it hard for early TM to have 18e-

Answer 4

they have a steric limitation
9 ligands cannot fit around early TM as they are too small

Question 5

18e- are usually seen in which TM

Answer 5

middle and late ones

Question 6

when is the 18e- rule less important

Answer 6

in complexes where bonding is more ionic

Question 7

describe a ligand

Answer 7

donated electrons
can donate electrons via a lone pair or a bond - use electron density in their HOMO to donate to the metals LUMO

Question 8

electron counting IONIC MODEL :: things we need to know

Answer 8

• ligand charge
• total ligand charge
• overall charge
• find OS of metal
• metal group number

Question 9

how can we find the oxidation state of a metal in a complex

Answer 9

the complex overall charge - total ligand charge

Question 10

how do we find the total number of d electrons in a metal

Answer 10

group number - oxidation state

Question 11

how do we find the total valence electron count of a complex

Answer 11

total metal d orbital electrons + ligand donated electrons