title: Crystal structure of 6-(p-tol-yl)benzo[b]naphtho[2,3-d]thio-phene and of an ortho-rhom-bic polymorph of 7-phenyl-anthra[2,3-b]benzo[d]thio-phene.
abstract: The title compounds, C23H16S, (I), and C26H16S, (II), are benzo-thio-phene derivatives in which the benzo-thio-phene moiety is fused with a naphthalene ring system in (I), and with an anthracene ring system in (II). In (I), the mean plane of the benzo-thio-phene ring system makes a dihedral angle of 2.28 (6)° with the naphthalene ring system, and a dihedral angle of 1.28 (6)° with the anthracene ring system in (II), showing that the fused units are essentially planar. In (I), the 4-methyl-benzene ring substituent makes a dihedral angle of 71.40 (9)° with the naphthalene ring system, while the phenyl ring substituent in (II) makes a dihedral angle of 67.08 (12)° with the anthracene ring system. In the crystals of both compounds, mol-ecules are linked by C-H⋯π inter-actions, leading to the formation of slabs parallel to (001) in (I) and to zigzag chains along [001] in (II). There are also offset π-π inter-actions present within the slabs in (I). In the crystal of (II), they link the chains, forming sheets parallel to (010). The triclinic polymorph of compound (II) has been reported [Sivasakthikumaranet al., (2012 ▸).J. Org. Chem.77, 9053-9071].
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: University of Neuchâtel, Institute of Physics, Rue Emile-Argand 11, CH-2000 Neuchâtel, Switzerland.
authors.forename: Helen
authors.initials: H
authors.lastname: Stoeckli-Evans
authors.affiliation: Department of Organic Chemistry, University of Madras, Guindy Campus, Chennai 600 025, India.
authors.forename: Muhamad
authors.initials: M
authors.lastname: Rafiq
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: C—H⋯π inter­actions; anthra[2,3-b]benzo[d]thio­phene; benzo[b]naphtho­[2,3-d]thio­phene; benzo­thio­phene; crystal structure; offset π–π inter­actions