Imidazole and thiazole derivatives: Synthesis, characterization, and nonlinear optical properties

Abstract

Imidazole and thiazole functionalities are crucial in designing blue-emitting materials, serving as electron-donating and electron-accepting groups. Two novel heterocyclic compounds, Benz and Phenz, were synthesized using the Radiszewski synthetic method, a metal-free approach. This design enhances hole and electron transport, carrier injection, and mobility, essential for optoelectronic applications. Highly functionalized imidazole and thiazole cores were developed through a mild condensation reaction between 4-methylthiazole derivatives and imidazole, benzimidazole, or phenanthroimidazole precursors, enabling regioselective synthesis with high yields and environmentally friendly reaction conditions. The synthesized molecules showed strong thermal stability and intense fluorescence in the 350–450 nm range, making them potential blue light-emitting applications. They also showed significant positive solvatochromic activity, indicating the influence of the solvent environment on their optical properties. Theoretical studies confirmed the experimental findings, with Benz showing a hyperpolarizability is 77.12×10⁻³⁰ esu, which is approximately 207 times greater than that of urea 0.37289×10⁻³⁰ esu.The calculated static first-order hyperpolarizability of the compound Phenz is 58.06×10⁻³⁰ esu, which is approximately 150 times greater than that of urea 0.37289×10⁻³⁰ esu. This enhancement in polarizability is due to extended conjugation, suggesting potential in non-linear optical applications and optoelectronic devices. These findings underscore the importance of rational molecular design in developing high-performance materials for emerging technologies.