New catalytically active conjugated microporous polymer bearing ordered salen-Cu and porphyrin moieties for Henry reaction in aqueous solution

Abstract

A catalytically active conjugated microporous polymer (SP-CMP-Cu) was facilely constructed with condensation polymerization of salen-Cu (salen = N,N′-bis(3-tertbutyl-5-formylsalicylidene) ethylenediamine) and pyrrole. The as-synthesized SP-CMP-Cu was completely characterized by powder X-ray diffraction (PXRD), Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), and energy-dispersive X-ray (EDX) analysis. The morphological features of SP-CMP-Cu were revealed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). According to the N₂ adsorption/desorption isotherm, the Brunauer–Emmett–Teller (BET) surface area of SP-CMP-Cu was calculated to be 252 m² g⁻¹ with a total pore volume of 0.178 cm³ g⁻¹. SP-CMP-Cu exhibited an outstanding catalytic performance for the Henry reaction in aqueous solutions with excellent conversion and good selectivity. Moreover, SP-CMP-Cu can be reused for up to five consecutive runs without any significant loss in its catalytic efficiency.