title: Comparative structural analysis of 2,7-diethoxy-1,8-bis(4-phenoxybenzoyl)naphthalene and its homologues: orientation of the 4-phenoxybenzoyl groups at the 1- and 8-positions of the naphthalene ring.
abstract: The title molecule, C40H32O6, possesses crystallographically imposed twofold symmetry, with the central two C atoms of the naphthalene unit sited on the rotation axis. The two 4-phenoxybenzoyl groups in the molecule are twisted away from the attached naphthalene unit, with a torsion angle of 66.76 (15)° between the naphthalene unit and the carbonyl group (C-C-C=O), and are oriented in mutually opposing directions (anti orientation). There is an apparent difference in the conformations of the 4-phenoxybenzoyl groups at the 1- and 8-positions of the naphthalene ring between the title molecule and its methoxy-bearing homologue [Hijikata et al. (2010). Acta Cryst. E66, o2902-o2903]. Whilst the 4-phenoxybenzoyl groups in 2,7-diisopropoxy-1,8-bis(4-phenoxybenzoyl)naphthalene [Yoshiwaka et al. (2013). Acta Cryst. E69, o242] are situated in the same anti orientation as the title molecule, those of 2,7-dimethoxy-1,8-bis(4-phenoxybenzoyl)naphthalene are oriented in the same direction with respect to the naphthalene ring system, i.e. in a syn orientation.
authors.affiliation: Department of Organic and Polymer Materials Chemistry, Tokyo University of Agriculture and Technology (TUAT), Koganei, Tokyo 184-8588, Japan.
authors.forename: Sayaka
authors.initials: S
authors.lastname: Yoshiwaka
authors.affiliation: Department of Organic and Polymer Materials Chemistry, Tokyo University of Agriculture and Technology (TUAT), Koganei, Tokyo 184-8588, Japan.
authors.forename: Kosuke
authors.initials: K
authors.lastname: Sasagawa
authors.affiliation: Instrumentation Analysis Center, Tokyo University of Agriculture and Technology (TUAT), Koganei, Tokyo 184-8588, Japan.
authors.forename: Keiichi
authors.initials: K
authors.lastname: Noguchi
authors.affiliation: Department of Organic and Polymer Materials Chemistry, Tokyo University of Agriculture and Technology (TUAT), Koganei, Tokyo 184-8588, Japan.
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Yonezawa
authors.affiliation: Department of Organic and Polymer Materials Chemistry, Tokyo University of Agriculture and Technology (TUAT), Koganei, Tokyo 184-8588, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Okamoto
keywords: C—H...π interactions; anti orientation; crystal structure; noncoplanarly accumulated aromatic rings; spatial organization; syn orientation