1. Do Now – Answer the questions about XeF4
What is this compound known as?
Why is this compound unusual?
Draw what you think the structure of this compound is
How many bonding pairs does it have?
How many lone pairs does it have?
What are the bond angles for this compound?

2. Isomerism in TM Complexes
Geometric – common occurrence where there are two ligands of one type different to the other ligands.

3. Cis-trans isomers of alkenes: Recap
E.g., but-2-ene (E-Z isomers)
(E)-but-2-ene - methyl groups attached to the C=C functional group are on opposite sides (the trans- isomer)
(Z)-but-2-ene - methyl groups attached to the C=C functional group are on same side (the cis- isomer)
The symbol Z comes from a German zusammen, which means together.
The symbol E comes from the German entgegen, which means opposite.

4. Isomerism in TM Complexes
Geometric Isomerism
e.g. [PtCl2(NH3)2]
cis
trans
Also [Ni(CN)4]2-

5. https://www. youtube. com/watch

6. To put it simply…
Cis-platin enables it to form a bond between the two strands of DNA in a cancer cell
This prevents it from separating
Prevents the cancer cells from dividing
The cell dies

7. More on Cisplatin [PtCl2(NH3)2] Square planar 2 stereoisomers
trans
More on Cisplatin
[PtCl2(NH3)2]
Square planar
2 stereoisomers
Cis- and trans –
Cis-diamminedichloroplatinum(II) = cisplatin
One of the most successful anticancer drugs
Trans- isomer does not have anti-cancer properties
Side-effects = nausea, vomiting, allergic reactions, hearing loss, kidney problems.
Risk of side effects higher with higher doses and increases as the total amount of cisplatin used increases over time.
Scientists still not sure of how ciplatin works – appears to be converted in cells into a reactive ions that bindds to DNA Stops cancer cells dividing, so treats the tumour.
Developed by Rosenberg in 1970s. Prof J Derek Woollins at University of St Andrews worked in Rosenberg’s group in the 1970s/1980s working on cisplatin ... He developed cancer because of the toxic chemicals that they were using and then was subsequently successfully treated with cisplatin.

8. Task 2
Complete Questions 1 and 2 on p6 and 7 of booklet

9. Summary Questions
Explain why you would expect the ICl4- ion to have a square planar shape
Draw the structures of the two cis-trans isomers of the IF2Cl2- ion.
Why are there no cis-trans isomers of the IFCl3- ion?

13. Cis-platin exam question