Crystal structure of monoaquatetra(3,5-dimethylpyrazole)copper(II) nitrate [Cu(C5H8N2)4(H2O)](NO3)2

The crystal structure of monoaquatetra(3,5-dimethylpyrazole)copper(II) nitrate [Cu(C₅H₈N₂)₄(H₂O)]×(NO₃)₂ is determined (Syntex P2₁ automated diffractometer, θ/2θ scan mode within the 2θ range 3–55° at a variable rate, V_min=5 deg/min, λMoK_α graphite monochromator, 5170/2349 measured/observed I_hk1, absorption taken into account experimentally, R_aniso=0.069). The parameters of the monoclinic unit cell are as follows: a=23.569(4), b=8.177(2), c=17.250(6) Å, β=121.65(2)°, V=2830(2) ų, Z=4C₂₀H₃₄CuN₁₀O₇, d_calc=1.388 g/cm³. The space group P2₁ was chosen by the process of structure solution and refinement. The structure is of island type. The complex cations [CuL₄(H₂O)]²⁺ and the (NO₃)^? anions form mixed layers in the planes parallel to (010) at y?0.36 and 0.87. The central atoms of two crystallographically independent complex cations [CuL₄(H₂O)]²⁺ are surrounded with five atoms (O_{H 2 O}+4N) with average Cu?O_{H 2 O} and Cu?N distances of 2.23(2) and 2.04(4), respectively, which form distorted trigonal bipyramids. The average bond lengths in the pyrazole rings are the following: N?N=1.40, N?C=1.40, (C?C)_ring=1.42, and C_ring?C_Me=1.50 Å.