1-(5-Carboxy-pent-yl)-2,3,3-trimethyl-3H-indol-1-ium bromide monohydrate

• Published in: Acta crystallographica. Section E, Structure reports online Vol. 66; no. Pt 1; pp. o171 - o172
• Main Authors: Winstead, Angela, Hart, Krystal, Hijji, Yousef M, Jasinski, Jerry P, Butcher, Ray J
• Format: Journal Article
• Language: English
• Published: United States International Union of Crystallography 01.01.2010
• Subjects: Organic Papers
• ISSN: 1600-5368; 1600-5368
• DOI: 10.1107/S1600536809049204

In the title compound, C(17)H(24)NO(2) (+)·Br(-)·H(2)O, the pentyl group chain in the cation extends nearly perpendicular [N-C-C-C = -64.4 (3)°] to the mean plane of the indole ring with the carboxyl end group twisted such that the dihedral angle between the mean planes of the indole and carb-oxy groups measures 43.2 (4)°. Both ions in the salt form inter-molecular hydrogen bonds (O-H⋯Br and O-H⋯O) with the water mol-ecule. As a result of the Br⋯H-O-H⋯Br inter-actions, a zigzag chain is formed in the c-axis direction. The crystal packing is influenced by the collective action of the O-H⋯O and O-H⋯Br inter-molecular inter-actions as well as π-π stacking inter-molecular inter-actions between adjacent benzyl rings of the indole group [centroid-centroid distance = 3.721 (13) Å] and inter-molecular C-H⋯π inter-actions between a methyl hydrogen and the benzyl ring of the indole group. The O-H⋯Br inter-actions form a distorted tetra-hedral array about the central Br atom. A MOPAC AM1 calculation provides support to these observations.