N-Heterocyclic Carbene–Palladium Functionalized Coordination Polymer (Pd-NHC@Eu-BCI) as an Efficient Heterogeneous Catalyst in the Suzuki–Miyaura Coupling Reaction

Abstract

In the present work, a new heterogeneous catalyst Pd-NHC@Eu-BCI was synthesized by introducing N-heterocyclic carbene–palladium active sites into a 2D coordination polymer [Eu(BCI)(NO3)2H2O]n (Eu-BCI) based on a 1,3-bis(carboxymethyl)imidazolium (HBCI) ligand. The catalyst was characterized by various analytical techniques such as X-ray photoelectron spectroscopy (XPS), inductively coupled plasma atomic emission spectroscopy (ICP-AES), energy-dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), powder X-ray diffraction (PXRD), infrared spectroscopy (IR) and thermogravimetric analysis (TGA). Catalytic activity of Pd-NHC@Eu-BCI was tested for the Suzuki–Miyaura cross-coupling reaction. The catalyst from the reaction mixture was easily recovered by filtration and still exhibited good catalytic activity and maintained its original structure after five cycles.

Keywords

• N-heterocyclic carbene–palladium
• coordination polymer
• heterogeneous catalyst
• Suzuki–Miyaura reaction