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

Two 4-(1H-1,2,4-triazol-1-yl)phenol (hptrz)-based transition metal complexes with different aromatic polycarboxylic acids as co-ligands, {[Cu-2(H2O)(4)(hptrz)(2)(btec)]center dot 2H(2)O}(n) (1) and [Cu(hptrz)(2)(H(2)btc)(2)]center dot H2O (2) (H(4)btec = benzene-1,2,4,5-tetracarboxylic acid, H(3)btc = 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 btec(4-) 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 lowdimensional coordination sphere into a high-dimensional supramolecular architecture by O-H center dot center dot center dot 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 btec(4-) anions.