Fig. 2.

Part of the crystal structure of (I), showing the formation of a (100) sheet. For the sake of clarity, H atoms not involved in the motif shown have been omitted. Intermolecular interactions are represented by dashed lines. Selected atoms are labelled. [Symmetry codes: (i) -x,y - 1/2,-z + 3/2; (ii) x + 1,-y + 3/2,z + 1/2; (iii) -x,y + 1/2,-z + 3/2; (iv) x,-y + 3/2,z + 1/2].