Smaragdyrins and Sapphyrins Analogues

Area of Science:

• Macromolecular Chemistry
• Organic Chemistry
• Supramolecular Chemistry

Background:

• Expanded porphyrins are versatile macrocycles with applications in catalysis, sensing, and medicine.
• Sapphyrins and smaragdyrins are 22π electron expanded porphyrins with five heterocyclic rings but distinct structures.
• While sapphyrins are well-studied, smaragdyrins have been less explored due to instability.

Purpose of the Study:

• To review the chemistry of 22π electron expanded porphyrins, specifically sapphyrins and smaragdyrins.
• To highlight structural differences and synthetic accessibility of these macrocycles.
• To discuss recent progress in smaragdyrin chemistry, particularly with the advent of stable oxasmaragdyrins.

Main Methods:

• Literature review focusing on sapphyrins and smaragdyrins.
• Comparative analysis of structural features and synthetic routes.
• Discussion of metal ion coordination and anion recognition properties.

Main Results:

• Sapphyrins possess a well-established chemistry due to efficient synthesis.
• Smaragdyrins are generally unstable, but oxasmaragdyrins offer a stabilized platform for exploration.
• Both macrocycles show potential in metal ion coordination and anion recognition.

Conclusions:

• Sapphyrins and smaragdyrins represent distinct classes of 22π electron expanded porphyrins.
• The development of stable oxasmaragdyrins has opened new avenues for smaragdyrin research.
• Further investigation into their coordination and recognition properties is warranted.