4-Bromo-1H-indole-2,3-dione

Abstract

The title compound, C8H4BrNO2, has a single planar molecule in the asymmetric unit with the non-H atoms possessing a mean deviation from planarity of 0.024 Å. The molecules dimerize in the solid state through N—H...O hydrogen bonds. There are intermolecular Br...O close contacts at 3.0430 (14) Å. The nine-membered rings of the isatins stack along [001] with parallel slipped π–π interactions [inter-centroid distance: 3.7173 (6) Å, inter-planar distance: 3.3110 (8) Å, slippage: 1.6898 (14) Å].

4-Iodo-1H-indole-2,3-dione

“…Similar IÁ Á ÁO interactions have been observed in 5-iodoisatin and its derivatives (Abid et al, 2008;Garden et al, 2006;Wang et al, 2014). The closely related 4-bromoisatin also exhibits a weak halogen-oxygen interaction in the solid state (Huang et al, 2016). The chains stack along [001] and are linked via parallel slippedinteractions [Cg2Á Á ÁCg2 ii = 3.699 (3) Å , where Cg2 is the centroid of ring C3-C8, inter-planar distance = 3.428 (2) Å , slippage = 1.383 Å , symmetry code (ii): x, Ày + 3 2 , z + 1 2 ], leading to the formation of undulating sheets lying parallel to (011).…”

7-Bromo-1H-indole-2,3-dione

“…The structure exhibits a near planar molecule with the non-hydrogen atoms possessing a mean deviation from planarity of 0.034 Å , with similar bond lengths and angles as those observed in isatin (Goldschmidt et al, 1950). The structure of the title compound demonstrates intermolecular Br1Á Á ÁO2 close contacts of 3.085 (2) Å , which are also observed in the structures of 4-bromoisatin and 6-bromoisatin (Huang et al, 2016;Turbitt et al, 2016). No such halogen interactions were observed for 5-bromoisatin, 7-fluoroisatin or 7-chloroisatin (Gurung et al, 2016;Mohamed et al, 2007Mohamed et al, , 2008Shankland et al, 2007;Sun et al, 2010).…”

5-Bromo-1H-indole-2,3-dione

“…The structure exhibits a near planar molecule with the nonhydrogen atoms possessing a mean deviation from planarity of 0.024 Å , with similar bond lengths and angles to those observed in isatin (Goldschmidt et al, 1950). The structure of other bromoisatins report short BrÁ Á ÁO contacts (Huang et al, 2016;Turbitt et al, 2016), which are not observed in 5-bromoisatin. The structures of N-subsistuted derivatives of 5bromoisatin have been reported (Kurkin et al, 2008;Maamri et al, 2012) with only one instance of a BrÁ Á ÁO interaction being observed (Kharbach et al, 2015).…”