A Photoresponsive Orthogonal Supramolecular Complex Based on Host-Guest Interactions.

Area of Science:

• Supramolecular Chemistry
• Photochemistry
• Materials Science

Background:

• Azobenzene derivatives are widely used in photoresponsive materials.
• Host-guest complexation is a key interaction in supramolecular chemistry.
• Controlling molecular interactions with light offers precise manipulation capabilities.

Purpose of the Study:

• To synthesize a novel green-light-responsive azobenzene derivative (ipAzo).
• To investigate the photoresponsive host-guest interactions of ipAzo with cyclodextrins.
• To develop an orthogonal photoresponsive supramolecular system.

Main Methods:

• Synthesis of tetra-ortho-isopropoxy-substituted azobenzene (ipAzo).
• Investigation of host-guest complexation between ipAzo and gamma-cyclodextrin (γ-CD) under different light conditions.
• Comparison with the azobenzene (Azo)/alpha-cyclodextrin (α-CD) system.

Main Results:

• Cis-ipAzo forms a strong host-guest complex with γ-CD, while trans-ipAzo binds weakly.
• This interaction is reversed compared to the traditional Azo/α-CD complex (strong for trans-Azo).
• An orthogonal photoresponsive supramolecular system was achieved by combining Azo/α-CD and ipAzo/γ-CD complexes.

Conclusions:

• A novel green-light-responsive ipAzo molecule was successfully synthesized.
• A unique photoresponsive host-guest interaction with γ-CD was demonstrated.
• The developed system allows for orthogonal light control over supramolecular assembly.