Figure 1 The molecular structure of title compound with the atom numbering scheme. Displacement ellipsoids are drawn at the 30% probability level. H atoms are presented as a small spheres of arbitrary radius. Symmetry codes: (i) -x + 1, y, -z - [{1\over 2}]; (ii) x, y + 1, z; (iv) -x, y, -z - [{1\over 2}]; (vii) 1 + x, y, z.  [article HTML]