Supramolecular

Question 1

What are crown ethers

Answer 1

…

Question 2

what are spherands?

Answer 2

pre organised receptor, crown ether with functinoal groups inside for extra coordination and rigidity, complexes called spheraplexes

Question 3

what are cryptands

Answer 3

3D crown ethers (3 branches, often with N at end)

Question 4

What are calixarenes?

Answer 4

Cylinder like structures with phenyl rings and R groups (e.g. iso butane) at one end and OH groups at other end. (pi)-Cation binding agents. Advantages: very specific, e.g. can be used for potassium ion channels, attach amino acid groups and allow flow of K+ and nothing else. Also think of electron rich benzene ring donating to electron deficient cations - stable.

Question 5

What are Sepulchrates?

Answer 5

Calixarene like structures with crytpand like binding between the two calixarene structures,

Question 6

Macrocylic Effect

Answer 6

HIGH AFFINITIY FOR MACROCYLIC STRUCTURES OVER THEIR ACYCLIC ANALOGUES!!!!!!!!

It is more entropically and enthalpically favoured to bind to a macrocylic than their acylcic anologue, this is because macrocylics are generally less soluble in solvent than ACYCLIC structures, and upon binding to normal structure, structure becomes insoluble in solution and therefore have energy of desolvation, unfavourable (high) enthalpy which doesn’t happen with macrocycle as it was never dissolved. Also entropically if a long chain structure has to fold to bind to a metal, entropy decreases, macrocycles are rigid structures and don’t experience same loss of entropy. Therefore it is more favourable for macrocyle to bind to metal.

Question 7

Chelate Effect

Answer 7

When have chelating ligand, more entropy to bind chelating ligand to say 2 sites occupied by two individual ligands, as when that chelating ligand binds, two ligands released and increase in entropy.

Question 8

What is the hydrophobic Effect?

Answer 8

Upon addition of non polar molecules to water, water surrounds themselves individually to each molecule, forming rigid structures around each molecule and WEAK bonding to each molecule (vs HB). Upon aggregation of non polar molecules, There is less surface area and less water molecules surrounding non polar molecules vs before, therefore increase in entropy and enthalpy (bonds)