Dithizone: redetermination and refinement of its crystal structure

Abstract

Crystals of dithizone are monoclinic, space group P2₁/n, a= 4.70(1), b= 22.25 (3), c= 11.95(2)Å, β= 98.0(3)°, U= 1 238 ų, Z= 4. The structure was determined from photographic data and refined to R 0.068 for 547 observed data. The molecule is near-planar, of approximate symmetry mm(C_2v) with the N–N–C–N–N chain extended and the C–S bond lying on the intersection of the mirror planes. The unique H atoms are bonded to N(1) and N(4). Bond lengths are: S–C 1.71, C–N 1.34, 1.35, N–N 1.29 and 1.30, and N–C(Ph) 1.38 and 1.39 (±0.01)Å. The π-electrons in the N–N–C–N–N system are extensively delocalised. Shortest intermolecular separations are between one molecule and those stacked above and below it parallel to a: N(1)⋯ N(3)(above) 3.38; N(2)⋯ N(4)(above) 3.30 Å; phenyl ring A, attached to N(1), lies directly below N(2) of the molecule above, while phenyl ring B, attached to N(4), lies directly above N(3) of the molecule below.