Structure determination of nitrato-κO-bis[2-(2-pyridyl-κN)amino-5,6-dihydro-4H-1,3-thiazine-κN]copper(II) nitrate via molecular modelling coupled with X-ray powder diffractometry

The title copper(II) coordination compound, C18H22CuN8O6S2 {[Cu(NO3)(PyTz)2]NO3}, was synthesized in the form of small crystals unsuitable for structure determination by single‐crystal X‐ray diffractometry. It was therefore characterized by molecular modelling coupled with X‐ray powder diffractometry [monoclinic, space group P21/n, a = 20.695 (7) Å, b = 8.054 (2) Å, c = 15.157 (4) Å, β = 112.09 (2)° and Rwp = 0.129]. The procedure used to resolve the structure followed direct space methods with a `Monte Carlo/parallel tempering' search algorithm, where the starting configuration was obtained by means of molecular mechanics. A final refinement was performed with the Rietveld method. Bond distances, bond angles and torsion angles were compared with those of similar compounds deposited in the Cambridge Structural Database.