CHARACTERIZATION OF ORGANIC-CRYSTAL PRODUCTS

The characterization of organic crystal products, based on internal st ructure using powder X-ray diffraction, was investigated with two subs tances. In the case of L-histidine alpha-ketoisocaproic acid complex e thanolate, the de-ethanolation rate increases when the crystal shows s tronger intensities of (002) reflection. The difference of the intensi ties of the (002) reflection was found to be caused by the internal st ructure (i.e. degrees of crystallinity and preferred orientation). The layer structure of L-histidine alpha-ketoisocaproic acid complex etha nolate [1] could explain the crystal structure having the tendency to take a structure with preferred orientation. In the case of the alpha- form of L-aspartic acid, the degree of preferred orientation varies ac cording to the crystallizing rates. Different crystal habits are noted among these samples. As a result of the simulation of a powder X-ray diffraction pattern from the crystal structure, the difference of the degree of preferred orientation is shown to reflect the global anisotr opic displacement of molecules.