Another example of diffraction is shown below. First we see x-ray diffraction from a single Sodium Crystal which has periodic locations of the atoms. However, the crystal structure determined by XRPD closely resembled that determined by SCXRD, only when the correct conformation of the neotame molecule had been chosen before detailed analysis of the XRPD pattern. Diffraction from crystals is a powerful tool. However, with 13 rigid bodies defined, Cerius2 gives a conformation of the neotame molecule, which is different from that determined by SCXRD.įor neotame anhydrate polymorph G, the unit cell dimensions calculated from XRPD were almost identical to those determined by SCXRD. Any in-depth description of diffraction, beyond Bragg’s law, requires the introduction of reciprocal space, which is also used in many other areas of physics. The XRPD pattern of polymorph G, analyzed by Cerius2 software, led to the same P2(1)2(1)2(1) space group and almost identical unit cell dimensions. The highly sampled single-molecule diffraction data of an imperfect crystal (averaged over the orientational symmetries of the point group) could be used to obtain a real-space image of the. Crystal diffraction is a vital tool in many fields of science, in particular solid state physics. The crystal structure of polymorph G was determined by single crystal X-ray crystallography (SCXRD) and also from the X-ray powder diffraction (XRPD) pattern using molecular modeling (Cerius2, Powder Solve module).įrom SCXRD, polymorph G crystals are orthorhombic with space group of P2(1)2(1)2(1) with Z = 4, unit cell constants: a = 5.5999(4), b = 11.8921(8), c = 30.917(2) A, and one neotame molecule per asymmetric unit. To determine the crystal structure of the neotame anhydrate polymorph G and to evaluate X-ray powder diffractometry (XRPD) with molecular modeling as an alternative method for determining the crystal structure of this conformationally flexible dipeptide.
0 kommentar(er)
