Refinement. The refinement was carried out against all reflections. The conventional R-factor is always based on F. The goodness of fit as well as the weighted R-factor are based on F and F2 for refinement carried out on F and F2, respectively. The threshold expression is used only for calculating R-factors etc. and it is not relevant to the choice of reflections for refinement.All the H atoms were discernible in difference Fourier maps and could be refined to reasonable geometry. According to standard procedures for organic compounds the H atoms bonded to C atoms were constrained to ideal positions. The isotropic atomic displacement parameters of hydrogen atoms were evaluated as 1.2*Ueq of the parent atom.The program used for refinement, Jana2006, uses the weighting scheme based on the experimental expectations, see _refine_ls_weighting_details, that does not force S to be one. Therefore the values of S are usually larger than the ones from the SHELX program.