Figure 1 A part of the polymeric structure of the title compound showing the atomic numbering scheme and 50% probability displacement ellipsoids for non-H atoms. Hydrogen bonds are shown as dashed lines. Atoms labelled with suffixes A-F are at the symmetry positions ([{1\over 2}] - x, [{1\over 2}] - y, -z), ([{1\over 2}] - x, [{1\over 2}] + y, [{1\over 2}] - z), (x, -y, [{1\over 2}] + z), (x, -y, z - [{1\over 2}]), ([{1\over 2}] - x, y - [{1\over 2}], [{1\over 2}] - z) and (- x, y, [{3\over 2}] - z), respectively.  [article HTML]