Question

1) Differentiate between “cryptand” and “cryptate”. Give one example for each and draw its structure.

2) Differentiate between “crown ether” and “cryptand”. Give one example for each and draw its
structure.

Answer 1

Cryptands are the cyclic compounds which results due to the polydenticity of legends.

It may consist of a ring and a inner structure which can trap the guest molecules.

Cryptate - when the guest molecules are trapped in the space between the rings then the compound formed is called cryptate .
The trapped guest molecule may be cation or anion.

This crypatate molecules can dissolve even in the non-polar solvents ,that's why this process is used for the catalysis because it can dissolve cations in the non-polar solvent when trapped.


Structure of the cryptant and the cryptate are shown in the figure .

Question 2 - In the cryptand oxygen and nitrogen both contribute to the denticity and where as in the case of the crown ether only the oxygen atoms are the dinars

The second important difference is that cryptand can be non- cyclic also on the other hand crown ether is essentially minocycline .
It is seen that cryptand ligands forms stronger bonds than cryptate due to high denticity.

The diagram of 18 crown 6 is shown in the figure .

Example of cryptand is shown in the solution of first answer.

Thank you