Figure 1 The crystal structure of the title compound with labeling and displacement ellipsoids drawn at the 50% probability level. [Symmetry codes: (i) -x,+1, -y + 2, -z + 1; (ii) -x + 1, y, -z + [{3\over 2}]; (iii) -x + [{1\over 2}], -y + [{1\over 2}], -z + 1.]  [article HTML]