Department of Solid State Physics, Indian Association for the Cultivation of Science
○Swastik Mondal Monika Mukherjee
Ab-initio structure determination of two hydroxy acetophenone derivatives, 1-(2-Hydroxy-5-methoxy-4methyl-phenyl)-ethanone (1) and 1-(2-Benzyloxy-5-methoxy-4methyl-phenyl)-ethanone (2), has been carried out from laboratory X-ray powder diffraction data. Intensity data were collected on a Bruker D8 Advance powder diffractometer using monochromatic CuKα1 radiation selected with an incident beam germanium monochromator with a step size of 0.02° (2θ) and counting time 25 sec-1. Both compounds, (1) and (2), belonged to the monoclinic system with space group P21/c [a = 8.66(3), b = 13.75(5), c = 8.13(3) Å, β = 108.27(4)° for (1) and a = 12.15(2), b = 16.41(2), c= 7.45(1) Å, β= 102.99(1)° for (2)]. The crystal structures have been solved by the direct space parallel tempering approach and refined by the Rietveld method. Final Rietveld refinement of the structures converged to Rp = 0.0886, Rwp = 0.1145 for (1) and Rp = 0.0989, Rwp = 0.1447 for (2) respectively. The molecule of (1) is essentially planar with the substituted methoxy carbon and keto oxygen atoms slightly deviating from the plane of the central benzene ring. The structure of (2) reveals that the molecule has two planar fragments constructed by methyl-phenyl and benzyloxy groups. There were strong indications of intra and inter molecular hydrogen bonds (D . . . A distance < 3.6 Å, D - H . . . A > 110°) stabilizing the molecular structures of (1) and (2).