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

The crystal structures of 4-(hydroxyl-phenyl)acetonitrile (A) 4-(nitro-phen yl)-acetonitrile (B) and 2-(4-methoxy-phenoxy)-ethanol (C), 1-bromomethyl-4 -nitrobenzene (D) and 1,4-dichloro-2-nitro-benzene (E) have been determined from X-ray powder diffraction data. Grid search and Rietveld refinement ha ve been used to determine the structure. The crystals of (A) and (B) are mo noclinic, space group P2(1)/c, Z=4 with cell parameters a = 6.771 Angstrom, b = 8.568 Angstrom, c = 11.766 Angstrom and beta = 93.47 degrees for (A) a nd a = 8.444 Angstrom, b = 5.942 Angstrom, c = 15.780 Angstrom. and beta = 100.06 degrees for (B); the crystals of (C) and (D) are orthorhombic, space group Pbcn, Z = 8, a = 38.00 Angstrom, b = 7.158 Angstrom and c = 6.493 An gstrom for (C) and space group P2(1)2(1)2(1), Z = 4, a = 6.506 Angstrom, b = 25.49 Angstrom and c = 4.735 Angstrom for (D). The crystals for (E) are t riclinic, space group P (1) over bar, Z = 2, a = 7.404 Angstrom, b = 8.273 Angstrom, c = 7.234 Angstrom, alpha = 109.6 degrees, beta = 112.9 degrees a nd gamma = 73.2 degrees. Chemical diagrams of all five compounds are depict ed in Fig. 1. Soft constraints have been applied to the molecules during Ri etveld refinement. The final R-p values obtained were 4.3 (A, Alphal), 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 Alphal diffractometer: and on a Guinier camera. The other the structures were only measured with the Guinier camera .