ABSTRACT
In the title compound, C(8)H(5)Br(2)NO(4), the endocyclic angles of the ring deviate significantly from the ideal value of 120 degrees. The substituents deviate from the plane of the ring, with large twist angles for the aldehyde, nitro and methoxy groups. The geometry of the molecule in the crystal is compared with that of the isolated molecule, as given by a self-consistent field molecular-orbital Hartree-Fock calculation. Only weak hydrogen bonds of the C-H.Br and C-H.O types are present in the crystal structure.
ABSTRACT
In the title compounds, C(6)H(5)NH(3)(+).H(2)PO(3)(-) and C(6)H(5)NH(3)(+).C(2)HO(4)(-).0.5H(2)O, the NH(3)(+) groups of the anilinium ion are ordered at room temperature. The rotation of these groups along the N-C(aryl) bond, which is often observed at room temperature in other anilinium compounds, is prevented by hydrogen bonds between the NH(3)(+) group and the anions. In both compounds, the geometry of the cation is significantly distorted from D(6h) to a symmetry close to C(2v). The angle ipso to the substituent is significantly larger than 120 degrees, as expected from the sigma-electron-withdrawing character of the NH(3)(+) group.
ABSTRACT
The title compound, C(27)H(37)N, which is intended to be included in the structure of a sulfonamide porphyrin for the preparation of Langmuir-Blodgett films, consists of a dodecyl chain linked to an anthracene molecule through an aminomethyl group. The angle between the least-squares plane of the anthracene and the dodecyl chain is 11.44 (8) degrees. The molecules are arranged in zigzag layers head-to-head, with the hydrocarbon chains side-by-side. The structure is stabilized by C-H.pi interactions, the strongest having an H.centroid distance of 2.63 A.
