Further study of (±)-mefloquinium chloride solvates. Crystal structures of the hemihydrate and monohydrate of (±)-mefloquinium chloride, from data collected at 120 K

The crystal structure of a monohydrate of (+/-)-mefloquinium chloride, (+/-)-[MEFHCl center dot(H(2)O)], has been obtained from data collected at 120 K. Further details of the crystal structure of a hemihydrate, (+/-)-[MEFHCl center dot 1/2(H(2)O)]. previously determined at room temperature, are also reported from data collected at 120 K. The structural data, along with X-ray powder patterns, infrared spectra (both mid and near IR ranges) and DSC data, provide definitive evidence for the two hydrates. Further attempts to completely resolve the crystal structure of a tetragonal solvated phase failed due to the considerable disorder, involving the solvates, either water or methanol, even at 120 K, however X-ray powder pattern and infrared spectral and DSC data for this phase are also reported. Comparisons of the data obtained for the hydrates in this study, with X-ray powder patterns and mid-infrared spectra of previously reported forms of (+/-)-mefloquinium chloride have highlighted erroneous assignments and allowed structural identification of previously and differently designated forms. (C) 2010 Elsevier B.V. All rights reserved.