Structure analysis of vanadyl phosphate intercalated with acetone

Structure analysis of vanadyl phosphate intercalated with acetone has been carried out using a combination of X-ray powder diffraction, infrared spect roscopy, and molecular mechanics simulations in Cerius(2) modeling environm ent. IR spectroscopy revealed the tautomerism in the interlayer space of VO PO4, i.e,, a partial conversion of acetone to the enrol form. Molecular sim ulations showed that this tautomerism leads to an increase of the orientati on disorder of guest species and consequently to the increase of the disord er in layer stacking. This disorder was confirmed by X-ray powder diffracti on. The basal spacing d(001) obtained from X-ray powder diffraction is 9.04 (15) Angstrom. The average value calculated by molecular mechanics simulati ons d(001) = 9.14(25) Angstrom is slightly higher due to the approximations used for the description of host-guest interaction. The positions and orie ntations of guest species and the mutual positions of two successive layers have been determined, including the characterization of disorder. (C) 2000 Academic Press.