title: Crystal structures of four indole derivatives with a phenyl substituent at the 2-position and a carbonyl group at the 3-position: the C(6) N-H⋯O chain remains the same, but the weak reinforcing inter-actions are different.
abstract: We describe the crystal structures of four indole derivatives with a phenyl ring at the 2-position and different carbonyl-linked substituents at the 3-position, namely 1-(2-phenyl-1H-indol-3-yl)ethanone, C16H13NO, (I), 2-cyclo-hexyl-1-(2-phenyl-1H-indol-3-yl)ethanone, C22H23NO, (II), 3,3-dimethyl-1-(2-phenyl-1H-indol-3-yl)butan-1-one, C20H21NO, (III), and 3-benzoyl-2-phenyl-1H-indole, C21H15NO, (IV). In each case, the carbonyl-group O atom lies close to the indole-ring plane and points towards the benzene ring. The dihedral angles between the indole ring system and 2-phenyl ring for these structures are clustered in a narrow range around 65°. The dominant inter-molecular inter-action in each case is an N-H⋯O hydrogen bond, which generates a C(6) chain, although each structure possesses a different crystal symmetry. The C(6) chains are consolidated by different (C-H⋯O, C-H⋯π and π-π stacking) weak inter-actions, with little consistency between the structures.
authors.affiliation: Department of Chemistry, University of Aberdeen, Meston Walk, Aberdeen AB24 3UE, Scotland.
authors.forename: Jamie R
authors.initials: JR
authors.lastname: Kerr
authors.affiliation: Department of Chemistry, University of Aberdeen, Meston Walk, Aberdeen AB24 3UE, Scotland.
authors.forename: Laurent
authors.initials: L
authors.lastname: Trembleau
authors.affiliation: Department of Chemistry, University of Aberdeen, Meston Walk, Aberdeen AB24 3UE, Scotland.
authors.forename: John M D
authors.initials: JM
authors.lastname: Storey
authors.affiliation: Department of Chemistry, University of Aberdeen, Meston Walk, Aberdeen AB24 3UE, Scotland; Fundação Oswaldo Cruz, Instituto de Tecnologia em Fármacos-Far Manguinhos, 21041-250 Rio de Janeiro, RJ, Brazil.
authors.forename: James L
authors.initials: JL
authors.lastname: Wardell
authors.affiliation: Department of Chemistry, University of Aberdeen, Meston Walk, Aberdeen AB24 3UE, Scotland.
authors.forename: William T A
authors.initials: WT
authors.lastname: Harrison
keywords: C(6) chain; N—H⋯O hydrogen bond; crystal structure; indole; weak inter­actions