A layered amino-functionalized zinc-terephthalate metal organic framework: Structure, characterization and catalytic performance for Knoevenagel condensation

A new stable mixed-ligand metal organic framework Zn-2(tpt)(2)(2-atp)I-2 1 (tpt = tris (4-pyridyl) triazine, 2-atp = 2-aminoterephthalate) with split channels has been synthesized and characterized. The nitrogen containing ligands tpt and 2-atp are selected to create attractive basic sites for the catalyst. The Knoevenagel condensation between benzaldehyde and the active hydrogen compound (ethyl cyanoacetate or malononitrile) is carried out using compound 1 as solid basic catalytic support. The test results indicate that 1 is an efficient base catalyst with selective catalytic properties. It gives 37% and 99% yield respectively for the condensation products ethyl (E)-alpha-cyanocinnamate and 2-benzylidenemalononitrile. TG data show that the solid catalyst sample is fairly thermally stable. The compound does not show any signs of decomposition until 420 degrees C. PXRD data support that the catalyst remains its crystalline and framework stability after the catalysis process. These characters make it easily to be regenerated for the next cycle. (C) 2011 Elsevier B.V. All rights reserved.