Syntheses and molecular structures of copper(II) complexes with 1,3,5-tris(pyrazol-1-ylmethyl)benzene

Abstract

A new trifunctional ligand, 1,3,5-tris(pyrazol-1-ylmethyl)benzene (L), has been prepared. It reacts with 1 equivalent of copper(II) perchlorate to form the complex [CuL₂(ClO₄)₂(H₂O)₂]1 and with 1.5 equivalents of copper(II)(chloride to form [{Cu₃L₂Cl₆(H₂O)₂}_n]3. The macromolecular complex [{Cu₂L₂Cl₂(ClO₄)₂(H₂O)₄}_n]2 was formed by the reaction of 1 with 1 equivalent of CuCl₂. Complex 3 can also be prepared from 2 with 1 equivalent of CuCl₂ or from 1 with 2 equivalents of CuCl₂. The mixed-metal complex [{Cu₂CoL₂Cl₆(H₂O)₃}_n]4 was prepared from 2 with cobalt(II) chloride. The molecular structures of complexes 1, 2 and 4 have been characterized by X-ray diffraction: 1, monoclinic, space group P2_1′, a= 10.255(1), b= 20.218(3), c= 10.316(2)Å, β= 106.21(1)°, Z= 2;2, monoclinic, space group P2₁/c, a= 11.288(2), b= 13.633(3), c= 15.173(3)Å, β= 104.635(15)°, Z= 2; 4, monoclinic, space group C2/c, a= 7.473(3), b= 22.137(7), c= 28.155(10)Å, β= 96.21(3)°, Z= 4. The co-ordination sphere of copper(II) in 1 and 2 is distorted square pyramidal and 2–4 have polymeric structures.