Figure 1 The molecular structure of the title compound, showing the asymmetric unit extended to show the coordination geometry for the Na+ ion. Displacement ellipsoids are drawn at the 50% probability level. H atoms are represented as small spheres of arbitrary radii (symmetry codes: (i) x + [{1\over 2}], y - [{1\over 2}], z; (ii) -x + 2, y, -z + [{3\over 2}]; (iii) -x + [{5\over 2}], y - [{1\over 2}], -z + [{3\over 2}]).  [article HTML]