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

Abstract

4,6-Dibromo-2,3,3-trimethyl-3H-indole, C11H11Br2N, 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, C12H14Br2N+·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.