In the title indole derivative, C16H10BrCl2NO, the dihedral angle between the mean plane of the indole ring system and the mean plane of the disordered 2-bromo-phenyl ring is 77.6 (1)°. The non-H atoms of the chloracetyl group are essentially coplanar with the indole core. In the crystal, pairs of mol-ecules are face-to-face embraced via two weak C-H⋯O hydrogen bonds, forming inversion dimers with an inter-planar distance between two parallel indole planes of 3.360 (3) Å. These dimers are connected by head-to-head Cl⋯Cl inter-molecular contacts to build a two-dimensional mol-ecular sheet parallel to (101). Neighbouring mol-ecular sheets are stacked together to construct the three-dimensional structure by further short Cl⋯Cl inter-molecular contacts. The atoms of the bromo-phenyl group were refined as disordered over two sets of sites with refined occupancies of 0.61 (2) and 0.39 (2).
Keywords: centrosymmetric dimer; crystal structure; hydrogen bonding; indole derivative; synthesis.