Crystal structures and Hirshfeld analysis of 4,6-di­bromo­indole­nine and its quaternized salt

4,6-Di­bromo-2,3,3-trimethyl-3H-indole, C(11)H(11)Br(2)N, exists as a neutral mol­ecule in the asymmetric unit. The asymmetric unit of 4,6-di­bromo-2,3,3-trimethyl-3H-indol-1-ium iodide, C(12)H(14)Br(2)N(+)·I(−), contains one organic cation and one iodine anion. The positive charge is localized on the quaternized nitro­gen atom. In the crystal, mol­ecules of 4,6-di­bromo­indole­nine are linked by C—Br⋯π halogen bonds, forming zigzag chains propagating in the [001] direction. The mol­ecules of the salt form layers parallel to the (010) plane where they are linked by C—H⋯Br hydrogen bonds, C—Br⋯Br and C—Br⋯I halogen bonds. The Hirshfeld surface analysis and two dimensional fingerprint plots were used to analyse the inter­molecular contacts present in both crystals.