Photochromic Dithienylethene-Containing Boron(III) Ketoiminates: Modulation of Photo-Responsive Behavior through...

Area of Science:

• Organic Chemistry
• Materials Science
• Photochemistry

Background:

• Dithienylethenes are photochromic compounds with potential applications in molecular switches.
• Boron(III) ketoiminates offer unique electronic and structural properties.
• Controlling photochromic behavior in organic materials is crucial for device development.

Purpose of the Study:

• To synthesize and characterize novel dithienylethene-containing boron(III) ketoiminates and their β-ketoimine ligands.
• To investigate the influence of substituents on the photochromic properties of these compounds.
• To understand the mechanism behind the observed differences in photochromism.

Main Methods:

• Synthesis of β-ketoimine ligands and boron(III) ketoiminate complexes.
• Characterization using spectroscopic and analytical techniques.
• Photophysical, electrochemical, and photochromic property evaluation.

Main Results:

• Successful synthesis and characterization of target compounds.
• Photocyclization was suppressed with a phenyl substituent on the nitrogen atom.
• Photochromism was observed when the phenyl group was replaced by a bulky mesityl group.
• Steric hindrance from the mesityl group restricted molecular rotation, enabling photochromism.

Conclusions:

• The steric effect of substituents on the β-ketoiminate core significantly impacts the photochromic behavior of dithienylethene-containing boron(III) ketoiminates.
• Bulky groups like mesityl can promote photochromism by inhibiting molecular rotation.
• These findings provide insights into the design of novel photochromic materials.