Synthesis of chromene derivatives in the presence of mordenite zeolite/MIL-101 (Cr) metal-organic framework composite as catalyst

In the present study, the synthesis of mordenite zeolite/MIL-101(Cr) metal-organic framework (MOF) composite [MOR/MIL-101(Cr)] using the ship in a bottle method was suggested. The properties of prepared composite and individual MOF and MOR zeolite were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption-desorption measurement, and thermogravimetric analysis (TGA). The XRD results indicated diffraction peaks for each compound (MOR and MOF) in composite. The SEM and TEM images showed the formation of plates MOR (with size of 2.5 x 3 mu m) along with spherical particles MIL-101. The Brunauer-Emmett-Teller results showed that the surface area of the composite was smaller than individual MOF and MOR zeolite. Based on TGA plots, the hybrid zeolite/MOF composite was more thermally stable compared with the isolated MIL-101(Cr). The composite was functionalized by post-synthetic modification to obtain acid-base bifunctionality (HMOR/MIL-101-ED) for the synthesis of chromene derivatives. The acidity from framework Al-O(H)-Si sites in MOR and basicity from amine groups in MIL-101 were obtained by post-synthetic modification.