Triazine-based mesoporous organic polymers as palladium supports: physicochemical properties, porosity and catalytic performance in Suzuki coupling reaction

Abstract

This article reports the preparation of new mesoporous triazine-based organic polymers and their characterization. The polymers were synthesized via a nucleophilic condensation reaction between cyanuric chloride and bisphenols or aromatic diamine linkers. As a result, two types of triazine-based polymers were prepared: triazine-ether and triazine-amine polymers. The polymers reveal a mesoporous nature with surface area values ranging between 345 and 1275 m² g⁻¹ and mesopore volume between 0.273 and 1.03 cm³ g⁻¹. These values were determined from argon gas isotherms at 87 K. The pore size distribution also confirmed the micro–mesoporosity, which reached up to 3.0 nm for all polymers. The triazine-amine polymer shows good thermal oxidative stability up to 450 °C. Motivated by the mesopore size, the new polymers were also employed as palladium nanoparticle supports. The X-ray diffraction technique indicated the successful incorporation of palladium nanoparticles, and Fourier transform infrared measurements proved that the framework of the polymers was retained after forming palladium supports. To ensure the catalytic reactivity of palladium nanoparticles, we employed one example as a catalyst in a Suzuki coupling reaction. The catalyst exhibited remarkable recyclability, maintaining catalytic efficiency through seven cycles, thereby enabling the use of palladium-loaded triazine-based polymeric catalysts in a variety of organic reactions in future. © 2023 Society of Industrial Chemistry.