The first salamo-type mixed-ligand Cu(II) coordination polymer: Synthesis, crystal structure and theoretical studies

Abstract

In this work, a copper(II) coordination polymer [Cu2(L1)(L2)(NO3)]n·nCH3OH (Cu(II)-CP) with different structures of mixed salamo-type ligands was constructed for the first time. Single crystal X-ray diffraction analysis showed that the Cu(II)-CP asymmetric unit consists of two copper(II) atoms, fully deprotonated (L1)−, (L2)2− ligand units, one NO3− anion and one molecule of crystallized methanol. The two metallized ligand units are bridged by two oxygen atoms of NO3− to form unique mixed-ligand copper(II) coordination polymer. In addition, the six coordination atoms around the two Cu(II) atoms are all arranged in a distorted octahedral geometry. In the molecular structure of Cu(II)-CP, neighbouring molecules interact through intermolecular hydrogen bonds to form a two-dimensional supramolecular structure. Intermolecular interactions and molecular stability were further investigated by Hirshfeld surface analysis and other theoretical calculations. Finally, the antimicrobial activities of both ligands and Cu(II)-CP were investigated and found to exhibit excellent antibacterial activities.