title: Two anilinium salts: anilinium hydrogenphosphite and anilinium hydrogenoxalate hemihydrate
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.
authors.affiliation: Departamento de Fisica, Faculdade de Ciencias e Tecnologia, Universidade de Coimbra, P-3004-516 Coimbra, Portugal. jap@pollux. fis.uc.pt.
authors.initials: JA
authors.lastname: Paixao
authors.lastname: Matos Beja A
authors.lastname: Ramos Silva M
authors.initials: J
authors.lastname: Martin-Gil