Temperature-dependent crystal structure analysis of methyl iodide by high-resolution neutron powder diffraction

High resolution neutron powder diffraction data recorded at 4.5 K confirm the orthorhombic structure of methyl iodide reported previously by Kawaguchi et al. (1973) from an X-ray single-crystal study at 193 K. The present study, using neutron powder diffraction, provides more precise structural parameters and reliable atomic co-ordinates for the hydrogen atoms enabling the methyl group libration to be analysed as a function of temperature up to 193 K.

[1]  M. Prager,et al.  The lattice and rotational dynamics of the methyl halides described by pair potentials based on universal force fields. , 2004, The Journal of chemical physics.

[2]  J. E. Boggs,et al.  The Equilibrium C–Cl, C–Br, and C–I Bond Lengths from Ab Initio Calculations, Microwave and Infrared Spectroscopies, and Empirical Correlations , 2003 .

[3]  P. Fertey,et al.  An Easy Method for the Determination of Debye Temperature from Thermal Expansion Analyses , 1998 .

[4]  A. J. Horsewill Rotational tunnelling in organic molecules , 1992 .

[5]  W. Chen,et al.  The millimeterwave spectrum of germyl fluoride: Determination and comparison of the effective, substitution, and equilibrium structures , 1991 .

[6]  M. Prager,et al.  Inelastic incoherent neutron scattering study of the methyl rotation in various methyl halides , 1987 .

[7]  A. Anderson,et al.  Raman and infrared spectra of crystalline methyl iodide , 1984 .

[8]  S. Brodersen,et al.  Determination of A0 and Dk for CD3I from the ν4 Raman and IR bands , 1983 .

[9]  K. Trueblood,et al.  Internal molecular motions in crystals. The estimation of force constants, frequencies and barriers from diffraction data. A feasibility study , 1983 .

[10]  E. Prince,et al.  Refinement of the structure of solid nitromethane , 1980 .

[11]  T. Shimanouchi,et al.  Raman spectra and crystal structures of methyl halides , 1976 .

[12]  A. W. Pryor,et al.  Thermal vibrations in crystallography , 1975 .

[13]  Y. Hayafuji,et al.  The Crystal Structures of Methyl Bromide and Methyl Iodide , 1973 .

[14]  K. N. Trueblood,et al.  On the rigid-body motion of molecules in crystals , 1968 .