Synthesis, crystal structure and catalytic property of a highly stable 3D Cu(II)-organic framework

Abstract

A three-dimensional (3D) Cu(II)-based MOF, [CuL·Cl]n (namely complex 1), was successfully generated through the in-situ reaction of CuCl2, NaN3, and 4-(4-cyanostyryl)pyridine. Notably, –CN and N3− can directly react to form a tetrazolate group during the crystal growth process. This reaction was further proved by single crystal X-ray diffraction data. Thanks to the excellent stability, various N-donors as Lewis basic sites and Cu(II) centres as Lewis acid sites, the as-made complex 1 has a potential application as a bifunctional heterogeneous catalyst for the CO2 cycloaddition reaction and Knoevenagel condensation reaction. In addition, complex 1 has the excellent recyclability for both reactions at least six cycles.