Ligand geometry controlling Zn-MOF partial structures for their catalytic performance in Knoevenagel condensation.

A series of novel Zn-MOFs {1Zn: [Zn(NIA) 2 (3-bpdh) 2 ]; 2Zn: [Zn(NPA) 2 (4-bpdh) 2 H 2 O]; 3Zn: [Zn 2 (CHDA) 4 (3-bpd) 2 ]} were constructed by dicarboxylic acid and N , N '-bis(pyridine-yl-ethylidene)hydrazine. Ligand geometry revealed 1D to 3D Zn-MOF crystal topologies, whose combined-mode could be affected by the conditions. All these conditions affected the micro-nano crystal morphologies, namely 1Zn micro-sheets or nanospheres, 2Zn micro-clusters or micro-stick, and 3Zn micro-clusters or hollowspheres that were obtained. The catalysts exhibited 100% selectivity for Knoevenagel condensation reactions, among which the benzaldehyde conversion rate of the 3Zn hollowspheres was the highest, reaching a peak of 90%.