All Visible Light Switch Based on the Dimethyldihydropyrene Photochromic Core

Area of Science:

• Photochemistry
• Supramolecular Chemistry
• Materials Science

Background:

• Photochromic compounds enable light-controlled molecular switching.
• Visible light-responsive systems are desirable for biological and electronic applications.

Purpose of the Study:

• To synthesize and characterize novel photoswitchable compounds operating under visible light.
• To investigate the photochromic behavior of dimethyldihydropyrene (DHP)/cyclophanediene (CPD) systems linked to bipyridine or ruthenium complexes.

Main Methods:

• Spectroscopic studies (UV-Vis absorption, NMR) to monitor isomerization.
• Computational studies (DFT) to understand electronic properties and reaction mechanisms.
• Synthesis of DHP/CPD coupled with bpy or Ru(bpy)3 moieties via a pyridinium bridge.

Main Results:

• Two novel photoswitchable compounds were successfully synthesized.
• The DHP to CPD isomerization (red light, >630 nm) and CPD to DHP conversion (blue light, 460 nm) were confirmed.
• Reversible and unambiguous photochromic switching was achieved using visible light.

Conclusions:

• The developed all-visible photoswitchable systems offer precise control over molecular states.
• These compounds show promise for applications in biological imaging, sensing, and molecular electronics.