title: Structure determination of the stable anhydrous phase of alpha-lactose from X-ray powder diffraction.
abstract: The stable anhydrous form of alpha-lactose has been obtained by the dehydration of alpha-lactose monohydrate in methanol. An X-ray powder diffraction pattern was recorded at room temperature with a laboratory diffractometer equipped with an INEL curved sensitive detector CPS120. The starting structural model of this form was found by a Monte-Carlo simulated annealing method. The structure was obtained through Rietveld refinements and the minimization of crystalline energy for the localization of the H atoms of the hydroxyl groups. Soft restraints were applied to bond lengths and angles. Networks of O-H...O hydrogen bonds account for the crystalline cohesion. A comparison is made between the hydrogen-bond networks of this form and those of the monohydrate and hygroscopic anhydrous forms of alpha-lactose.
authors.affiliation: Laboratoire de Dynamique et Structure des Matériaux Moléculaires (UMR CNRS 8024), UFR de Physique, Bâtiment P5, Université des Sciences et Technologies de Lille, 59655 Villeneuve d'Ascq CEDEX, France.
authors.forename: Cyril
authors.initials: C
authors.lastname: Platteau
authors.forename: Jacques
authors.initials: J
authors.lastname: Lefebvre
authors.forename: Frederic
authors.initials: F
authors.lastname: Affouard
authors.forename: Jean François
authors.initials: JF
authors.lastname: Willart
authors.forename: Patrick
authors.initials: P
authors.lastname: Derollez
authors.forename: Franck
authors.initials: F
authors.lastname: Mallet