Sono-synthesis of basic metal-organic framework for reusable catalysis of organic reactions in the eco-friendly conditions

Abstract

A functionalized Metal-Organic Framework (MOF) TMU-42 decorated with azine group has been synthesized with solvothermal and sonochemical strategies and identified by various chemo-physical techniques. Utilizing ultrasonic irradiation caused ultrafast formation of TMU-42 nanorods within 5 ​min, while its bulky form takes 48 ​h. The effect of various parameters including initial concentrations and reaction time on the morphology and size of the nanostructure was studied and compared with its bulky form. The catalytic activity of two bulk and nanorod TMU-42 and bulk TMU-43 frameworks toward the Knoevenagel and Henry reactions were evaluated and compared. TMU-42 has shown superior activity with excellent conversion (with decreasing reaction time up to 5 ​min) due to its active and size-selective pores in the eco-friendly sono-conditions. This result can be attributed to its basic azine functionalized. The sonocatalytic reaction was further performed to inspect its profound effect on the reaction time. Furthermore, the main structure of the catalyst was preserved and easily reused after the fourth catalytic cycle without remarkable loss in its catalytic activity.