title: 4-nitro-9,10-dihydrophenanthrene and a polymorphic form of 4-nitrophenanthrene.
abstract: The crystal structures of 4-nitro-9,10-dihydrophenanthrene, C14H11NO2, (I), and 4-nitrophenanthrene, C14H9NO2, (II), the latter having two crystallographically independent molecules, show that the molecules are not planar. The dihedral angles between the phenyl rings of the biphenyl skeletons are 28.64 (8) degrees for (I), and 10.34 (15) and 11.75 (13) degrees for the two molecules of (II). The differences in the dihedral angles have an effect on the photochemical reactivity of the molecules.
authors.affiliation: Department of Chemistry and Materials Science, Tokyo Institute of Technology, Oookayama 2, Meguro-ku, Tokyo 152-8551, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Sekine
authors.forename: H
authors.initials: H
authors.lastname: Uekusa
authors.forename: Y
authors.initials: Y
authors.lastname: Ohashi
authors.forename: K
authors.initials: K
authors.lastname: Yoshimura
authors.forename: M
authors.initials: M
authors.lastname: Yagi
authors.forename: J
authors.initials: J
authors.lastname: Higuchi