title: Reinterpretation of the monohydrate of clarithromycin from X-ray powder diffraction data as a trihydrate.
abstract: Noguchi, Fujiki, Iwao, Miura & Itai [Acta Cryst. (2012), E68, o667-o668] recently reported the crystal structure of clarithromycin monohydrate from synchrotron X-ray powder diffraction data. Voids in the crystal structure suggested the possible presence of two more water molecules. After successful location of the two additional water molecules, the Rietveld refinement still showed minor problems. These were resolved by noticing that one of the chiral centres in the molecule had been inverted. The corrected crystal structure of clarithromycin trihydrate, refined against the original data, is now reported. Dispersion-corrected density functional theory calculations were used to check the final crystal structure and to position the H atoms.
authors.affiliation: Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark. jaccovandestreek@yahoo.co.uk
authors.forename: Jacco
authors.initials: J
authors.lastname: van de Streek
mesh_terms: D017291:Clarithromycin / Q000737:chemistry*; D018360:Crystallography, X-Ray; D015394:Molecular Structure; D033362:Powder Diffraction; D014867:Water / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D014867:Water; D017291:Clarithromycin