Crystal structure of the dichlorobis(1-allyltetrazole-N4)copper(II) complex [Cu(1-CH2=CHCH2−N4CH)2Cl4/2]∞∞

The crystal structure of the dichlorobis(1-allyltetrazole-N⁴)copper(II) complex was determined by X-ray diffraction analysis. The crystals are monoclinic, a=14.233(3), b=6.755(1), c=7.273(1) Å, β=104.63(3)°, V_cell=676.6(2), ų, space group P2₁/c, Z=4, d_calc=1.741g/cm³, d_msd=1.69 g/cm³, CAD-4, λMoK_α radiation, R_F=0.0377 for 520 F_hkl>4σ(F_hkl) and 0.0560 for all 872 independent reflections. The structure is layered; the coordination polyhedron of copper is a square bipyramid, in which the equatorial positions are occupied by two chlorine atoms (Cu?Cl 2.27(2)–2.31(2) Å) and two N⁴ atoms of planar tetrazole ligands, whereas the axial positions are occupied by two chlorine atoms of the neighboring molecules of the complex (Cu?Cl 2.97(2)–3.01(2) Å). The sublattice of chlorine atoms is disordered in such a way that the CuCl_4/2]_∞∞ layer is a superposition of two variants with weights 61(3) and 39(3)% and with similar geometrical characteristics: the equatorial chlorine atoms in variant A are replaced by the axial atoms in variant B and vice versa. The tetrazole ligand has the same position in both variants. In general, the crystal is a polytype with random alternation of A and B type blocks. It is shown that the compound is isostructural to the complex with 1-ethyltetrazole Cu(ettz)₂Cl₂], in which only variant B is realized.