BMP: Drug Desgin 1

Question 1

What are examples of intermolecular and intramolecular bonds?

List in terms of increasing charge seperation and state the type of bonding of each

Answer 1

1. Dispersion interactions(lipophillic)
2. Hydrophobic interactions (lipophillic)
3. Pi-Pi stacking interactions (lipophillic)
4. Carbon pi and anionic pi interacations (electrostatic)
5. Hydrogen bonding (H-binding)
6. Dipole - Dipole (electrostatic)
7. Ion- Dipole (electrostatic)
8. Ion - ion (electrostatic)

Question 2

What type of bonding is hydrogen bonding a special case of?

Answer 2

Dipole - Dipole

Question 3

Describe what is Carbon pi and cationic/ anionic bindnig?

Answer 3

1. A benzene (Carbon cyclic compound with pi cloud) is electon rich due to the electrons being delocalised in the pi cloud. This means the ring is able to electrostatically interact with cations.
2. A benzene ring which contains a nitrogen is electron deficient. The Nitrgonen is very electronegatve so pulls the delocalised electrons towards it, making the pi cloud electron deficnent. This means that anions can electrostaically interact with the pi cloud.

Question 4

What are the purpose of:

1. Intramolecular bonds
2. Intermolecular bonds

Answer 4

1. Covalent bonds reponsible for the drug framework
2. Form interactions between drug and target

Question 5

What type of bonding are the following examples of:

1. Benze - Benzne
2. NH —- OH
3. Na+ — Cl-

Answer 5

1. Lipophillic (pi stacking)
2. H-bonding
3. Electrostatic bonding

Question 6

What are the strongest bonds?

Answer 6

Covalent

Question 7

1. What molecules are covalent bonds formed between?
2. What happens in covalent bonding?

Answer 7

1. Formed between non-metals
2. The more electronegative atom in the bond attracts a larger portion of the electron density/ electrons in the bond. This causes it to have a partial negatvie charge and the opposite atom to have a partial positive charge

Question 8

1. What type of bonding is ionic?
2. What happens in ionic bonding?
3. What weakens ionic bondng?

Answer 8

1. Intermolecular
2. Ionic interactions occur due to the attraction between atoms with large differences in electronegatively. The more EN atom abstracts valacne electrons from the less negative atom to form a positvely and negtively chatged ion
3. Polar solvent molecules

Question 9

1. How do lipophillic interactions occur?
2. Decribe the type of interactno

Answer 9

1. Occur due to temporary/ transient dipoles generated by motion of electrons in colvalent bonds
2. Weak, additive, increasw with molar mass

Question 10

Describe H-bonding

Answer 10

Occurs when Hydrogen is bonded to an electronegtaive atom (N,O) and interacts with their lone pait of electrons

Question 11

Describe how the strength of electrostatic bonds vary

Answer 11

• Stronger when their is strong charge seperation and weaker in the presence of partial charges
• Charge delocalisation (due to resonance) weakens the resulting electrostaic bonding. Where as charge localisation (due to lack of resonance delocalisation) results in stronger charges