Living in a cage is a restricted privilege.

Area of Science:

• Supramolecular Chemistry
• Coordination Chemistry

Background:

• Molecules with cage-like structures can encapsulate metal ions or anions.
• Unlike macroscopic cages, molecular cages allow ions to enter and exit based on thermodynamic control, not kinetic barriers.

Purpose of the Study:

• To review the development of cage compounds in metal and anion coordination chemistry over the past 50 years.
• To highlight the design principles and aesthetic appeal of synthetic cage molecules.

Main Methods:

• Review of literature on cage compounds in coordination chemistry.
• Analysis of thermodynamic principles governing guest-host interactions in molecular cages.

Main Results:

• Cage-shaped molecules enable highly selective recognition and binding of metal ions and anions.
• The design of these polycyclic hosts showcases synthetic ingenuity and offers aesthetic gratification.

Conclusions:

• Molecular cages represent a significant advancement in selective ion recognition.
• The field has evolved considerably over the last five decades, merging chemical functionality with aesthetic design.