Receptors for Neutral Guests

Question 1

What should effective hydrogen bond receptors be?

Answer 1

Complementary to desired guest

Preorganised and rigid - to avoid intramolecular hydrogen bond events

Question 2

Explain diagonal interactions

Answer 2

Purely repulsive - low K

Purely attractive - high K

Question 3

Give an example of a receptor that exploits the hydrophobic effect

Answer 3

Cyclophanes

Question 4

What are the two properties of cyclophanes that allow this?

Answer 4

1) Greasy and lipophilic - wouldn’t interact well with water inside, so the guest will sit inside
2) Binding at pH < 2 - four nitrogen atoms can be protonated so receptor will dissolve