Crystal structure of 5-[2-(2,4,6-tri-bromo-phen-yl)diazen-yl]tropolone.

The title compound {systematic name: 2-hy-droxy-5-[2-(2,4,6-tri-bromo-phen-yl)diazen-1-yl]cyclo-hepta-2,4,6-trien-1-one}, C(13)H(7)Br(3)N(2)O(2), is essentially planar, with an r.m.s. deviation of 0.054†à . The mol-ecular structure is fixed in the azo tautomer by intra-molecular C-H⋯N inter-actions, with O-H⋯O hydrogen bonds creating linked dimers. Charge-transfer inter-actions are observed, with the segregated stacks linked by Br⋯Br inter-actions.