title: Crystal structures of three indole derivatives: 3-ethnyl-2-methyl-1-phenyl-sulfonyl-1H-indole, 4-phenyl-sulfonyl-3H,4H-cyclo-penta-[b]indol-1(2H)-one and 1-{2-[(E)-2-(5-chloro-2-nitro-phen-yl)ethen-yl]-1-phenyl-sulfonyl-1H-indol-3-yl}ethan-1-one chloro-form monosolvate.
abstract: The title compounds, C17H13NO2S, (I), C17H13NO3S, (II), and C24H17ClN2O5S·CHCl3, (III), are indole derivatives. Compounds (I) and (II) crystalize with two independent mol-ecules in the asymmetric unit. The indole ring systems in all three structures deviate only slightly from planarity, with dihedral angles between the planes of the pyrrole and benzene rings spanning the tight range 0.20 (9)-1.65 (9)°. These indole ring systems, in turn, are almost orthogonal to the phenyl-sulfonyl rings [range of dihedral angles between mean planes = 77.21 (8)-89.26 (8)°]. In the three compounds, the mol-ecular structure is stabilized by intra-molecular C-H⋯O hydrogen bonds, generating S(6) ring motifs with the sulfone O atom. In compounds (I) and (II), the two independent mol-ecules are linked by C-H⋯O hydrogen bonds and C-H⋯π inter-actions, while in compound (III), the mol-ecules are linked by C-H⋯O hydrogen bonds, generating R 2 (2)(22) inversion dimers.
authors.affiliation: Department of Physics, RKM Vivekananda College (Autonomous), Chennai 600 004, India.
authors.forename: S
authors.initials: S
authors.lastname: Gopinath
authors.affiliation: Department of Physics, RKM Vivekananda College (Autonomous), Chennai 600 004, India.
authors.forename: K
authors.initials: K
authors.lastname: Sethusankar
authors.affiliation: Department of Organic Chemistry, University of Madras, Guindy Campus, Chennai 600 025, India.
authors.forename: Bose Muthu
authors.initials: BM
authors.lastname: Ramalingam
authors.affiliation: Department of Organic Chemistry, University of Madras, Guindy Campus, Chennai 600 025, India.
authors.forename: Arasambattu K
authors.initials: AK
authors.lastname: Mohanakrishnan
keywords: crystal structure; hydrogen bonding; indole derivatives; phenyl­sulfon­yl