Synthesis and crystal structure of Zn[(C6H5N3)4(H2O)2](ClO4)2 and Cu[(C6H5N3)4(H2O)2](ClO4)2

Two novel octahedral complexes with formula of Zn[(C6H5N3)4(H2O)2](ClO4)2 1 and Cu[(C6H5N3)4(H2O)2](ClO4)2 2 have been obtained by the reaction of benzotriazole (BTA) ligand with zinc(II) salt and copper(II) salt in ethanol–water solution, respectively. Elemental analysis, IR spectra and X-ray crystal structure analysis were carried out to determine the compositions and crystal structures of the two compounds. The complex 1 crystallizes in monoclinic C2/c space group, with lattice parameters a=13.838(2), b=13.374(4), and c=16.944(3) Å. β=103.206(9)°, V=3053.1(11) Å3, Z=4, R1=0.0411. The complex 2 crystallizes also in monoclinic C2/c space group, with lattice parameters a=13.919(7), b=13.380(7), and c=16.733(9) Å. β=103.206(9)°, V=3026 Å3, Z=4, R1=0.0423. The two complexes are isostructural. Both are mononuclear compounds, with similar coordination modes and packing arrangement in crystals. Every center metal ion is coordinated by four nitrogen atoms from four BTA ligands and two oxygen atoms from two water molecules, forming an octahedral coordination polyhedron.