Kdm. Harris et al., PREDICTING X-RAY-DIFFRACTION INTENSITY DISTRIBUTIONS FOR ONE-DIMENSIONAL INCLUSION-COMPOUNDS VIA LOCAL-DENSITY FUNCTIONAL CALCULATIONS, Journal of the Chemical Society. Faraday transactions, 89(12), 1993, pp. 2017-2021
Citations number
20
Categorie Soggetti
Chemistry Physical","Physics, Atomic, Molecular & Chemical
We investigate whether certain features of the X-ray diffraction (XRD)
pattern arising from the guest molecules in one-dimensional inclusion
compounds can be predicted and rationalized on the basis of the elect
ron-density distribution computed for the periodic guest structure in
the inclusion compound. Specifically, we note that in the XRD patterns
of diacyl peroxide/urea inclusion compounds, scattering in reciprocal
lattice planes (hkl)g with odd I is significantly more intense than t
hat in the adjacent reciprocal lattice planes with even I, whereas for
alkane/urea inclusion compounds there is a monotonic decrease in inte
nsity as I is increased. Local density functional methods have been us
ed to compute the electron-density distributions for the guest structu
res in the dioctanoyl peroxide/urea and decane/urea inclusion compound
s; and the methodology required to use this information to calculate t
he XRD intensities 1(hkl)g , as a function of I index, is described. I
t is demonstrated that XRD intensity distributions derived from the co
mputed guest electron densities do indeed predict correctly the contra
sting relationships between 1(hkl)g and I, observed experimentally, fo
r the diacyl peroxide/urea and alkane/urea inclusion compounds.