Two Cu(II) coordination polymers based on benzene-1,3,5-tricarboxylate and 1,2,4-triazolide ligands: their crystal structures and application of nanoparticles in anti-esophageal cancer activity evaluation

By reaction of 1,2,4-triazole (Htrz) and 1,3,5-benzenetricarboxylic acid (H3btc) with copper salts under hydrothermal conditions, two new mixed-ligand Cu(II)-coordination polymers [Cu5(Hbtc)4(trz)2(H2O)4](H2O)2 (1) and [Cu2(btc)(trz)](H2O)3 (2) have been successfully prepared. Their structures have been analyzed via the X-ray single-crystal diffraction method, powder X-ray diffraction measurements, and elemental analyses. The results have revealed that complex 1 is a three-dimensional pillar-layered network composed of octahedral Cu(II) formed Cu(II)-Hbtc2− layers pillared by the trz− ligands. Compound 2 features a three-dimensional network composed of planar Cu(II) node connected by the btc3− and trz− ligands. With the aid of a reflux treatment, both coordination polymers 1 and 2 could be prepared in nanoscale region. Moreover, we studied the anti-esophageal cancer of the two nanostructures via the standard MTT assay. The studies of anticancer activity have revealed that the coordination surrounding of the Cu(II) ion plays a key role in the resulting anticancer activities.