Proton-transfer lasers from solid polymeric chains with covalently bound 2-(2'-hydroxyphenyl) benzimidazole groups

Area of Science:

• Organic chemistry
• Polymer science
• Laser physics

Background:

• 2-(2'-hydroxyphenyl) benzimidazole derivatives are known for their photophysical properties.
• Intramolecular proton transfer (IPT) in the excited state is a key mechanism for their optical behavior.
• Polymer matrices can influence the performance of organic dyes.

Purpose of the Study:

• To investigate the lasing properties of novel 2-(2'-hydroxyphenyl) benzimidazole derivatives.
• To compare the performance of these derivatives when copolymerized with methyl methacrylate versus dissolved in poly(methyl methacrylate).
• To evaluate the impact of covalently binding the proton-transfer chromophore to a polymer chain on lasing efficiency and photostability.

Main Methods:

• Synthesis of new 2-(2'-hydroxyphenyl) benzimidazole derivatives.
• Copolymerization of derivatives with methyl methacrylate.
• Dissolution of derivatives in poly(methyl methacrylate) films.
• Pumping experiments using an N(2) laser.
• Analysis of lasing efficiency and dye photostability.

Main Results:

• The N(2) laser-pumped lasing properties of the synthesized benzimidazole derivatives were reported.
• Radiation mechanism confirmed to be intramolecular proton-transfer in the electronic excited state.
• Significant increases in both lasing efficiency and dye photostability were observed when the proton-transfer chromophore was covalently bound to the polymeric chain.
• Energy-conversion efficiencies comparable to those in liquid solutions were achieved in the polymer-bound system.

Conclusions:

• Covalent incorporation of proton-transfer chromophores into polymer chains enhances lasing performance.
• Polymer-bound benzimidazole derivatives offer a viable alternative to liquid solutions for laser applications.
• The study demonstrates a promising approach for developing stable and efficient polymeric laser materials.