Crystal structure determination of a series of benzene derivatives from powder data

Abstract

Abstract The crystal structures of 4-(hydroxyl-phenyl)-acetonitrile (A) 4-(nitro-phenyl)-acetonitrile (B) and 2-(4-methoxy-phenoxy)-ethanol (C), I-bromomethyl-4-nitro-benzene (D) and I,4-dichloro-2-nitro-benzene (E) have been determined from X-ray powder diffraction data. Grid search and Rietveld refinement have been used to determine the structure. The crystals of (A) and (B) are monoclinic, space group P21/c, Z = 4 with cell parameters a = 6.771 Å, b = 8.568 Å, c = 11.766 Å and β = 93.47° for (A) and a = 8.444 Å, b = 5.942 Å, c = 15.780 Å and β = 100.06° for (B); the crystals of (C) and (D) are orthorhombic, space group Pbcn, Z = 8, a = 38.00 Å, b = 7.158 Å and c = 6.493 Å for (C) and space group P212121, Z = 4, a = 6.506 Å, b = 25.49 Å and c = 4.735 Å for (D). The crystals for (E) are triclinic, space group P[unk], Z = 2, a = 7.404 Å, b = 8.273 Å, c = 7.234 Å, α = 109.6°, β = 112.9° and γ = 73.2°. Chemical diagrams of all five compounds are depicted in Fig. 1. Soft constraints have been applied to the molecules during Rietveld refinement. The final Rp values obtained were 4.3 (A, Alpha1), 8.8 (A), 5.0 (B), 8.7 (C), 6.6 (D) and 5.7% (E), respectively. Compound (A) was measured both on a Bragg-Brentano Alpha1 diffractometer and on a Guinier camera. The other the structures were only measured with the Guinier camera.