Unusual coordination of a chloride ion to six copper ions: Synthesis and crystal structure of copper(II) complexes with 4-(4-hydroxyphenyl)-1,2,4-triazole

Novel copper(II) complexes, molecular [Cu6(μ6-Cl)(μ3-OH)2(μ-L)6Cl9(H2O)3] · 3H2O (1) and polymeric [Cu(μ-L)(μ-OH)(H2O)2]Cl (2) (L = 4-(4-hydroxyphenyl)-1,2,4-triazole), have been prepared and characterized by X-ray structural analysis. Compound 1 appears to be an unusual example of a chloride ion with six equal Cu–Cl distances of 2.8397(3) Å. It has also been characterized by X-ray powder diffraction and magnetic measurements. Both complexes have distorted octahedral configurations of copper ions; the coordination cores are CuN2Cl2O2 or CuN2Cl3O (1) and CuN2O4 (2).

Graphical abstractNovel copper(II) complexes with substituted 1,2,4-triazole, molecular and polymeric, have been prepared and characterized. The molecular complex shows interesting coordination of Cl− to six copper ions with all six Cu–Cl bonds equal to 2.8397(3) Å. It shows mainly antiferromagnetic exchange interactions between the Cu2+ centers.Figure optionsDownload full-size imageDownload as PowerPoint slide