Designing a bifunctional metal-organic framework by tandem post-synthetic modifications; an efficient and recyclable catalyst for Suzuki-Miyaura cross-coupling reaction

Abstract

A new Cu/Pd bimetallic Cu-MOF-[Pd] was synthesized through covalent, dative and inorganic post-synthetic modifications. In order to achieve the Cu-MOF-[Pd], Zn-MOF (TMU-17-NH2) was initially selected and fabricated by grafting of salicylaldehyde via Schiff-base formation followed by complex formation with Pd(II). Then, the as-synthesis MOF, Zn-MOF-[Pd], was subjected as 3D-template to obtain Cu-MOF-[Pd] by transmetalation process. The Cu-MOF-[Pd] was characterized by FT-IR spectroscopy, atomic absorption spectroscopy (AAS), field emission scanning electron microscopy (FE-SEM), powder X-ray diffraction (PXRD), energy dispersive X-ray spectroscopy (EDS), and EDS mapping techniques. The feasibility of using Cu-MOF-[Pd] as a highly active recoverable catalyst was confirmed in the Suzuki–Miyaura cross-coupling reaction in a mixed water/ethanol solvent. The results show that this novel nano-composite could serve as an efficient bimetallic heterogeneous catalyst and reuse at least for 5 times without loss in activity.