Two new copper(II) complexes based on 4-(1H-1,2,4-triazol-1-yl)phenol and different co-ligands: synthesis, crystal structures, luminescent properties and magnetic behavior

Abstract

Two 4-(1H-1,2,4-triazol-1-yl)phenol (hptrz)-based transition metal complexes with different aromatic polycarboxylic acids as co-ligands, {[Cu2(H2O)4(hptrz)2(btec)]⋅2H2O}n (1) and [Cu(hptrz)2 (H2btc)2]·H2O (2) (H4btec = benzene-1,2,4,5-tetracarboxylic acid, H3btc = benzene-1,3,5-tricarboxylic acid), have been obtained, which were structurally characterized by single-crystal X-ray diffraction, elemental analysis, FT-IR spectra, thermogravimetric curves and luminescence spectra in detail. Structural analysis reveals that 1 is a 1-D infinite chain framework extended by btec4– anions, whereas 2 is isolated centrosymmetric mononuclear entities. In contrast, the neutral hptrz is a terminal ligand to complete the metal coordination sphere and it also helps to assemble the low-dimensional coordination sphere into a high-dimensional supramolecular architecture by O–H···O hydrogen-bonding interactions. Additionally, the high stability and luminescence emission suggest that 1 and 2 are good candidates for light emission materials. The magnetic features of 1 may be due to weak antiferromagnetic coupling between CuII ions which are separated by btec4– anions.