Figure 2 Crystal packing of the title compound. Hydrogen bonds are indicated by dashed lines. H atoms not involved in H-bonds are omitted for clarity. Symmetry codes: (i) -1 + x, -1 + y, z; (ii) 1 - x, 1 - y, -z; (iii) -x, -y, -z; (iv) -1 + x, y, z.  [article HTML]