Optimum resolution data of X-ray pow- der diffraction for 7-amino desacetoxy cephalospo- ranic acid(7-ADCA) were collected from an X′ Pert Pro MPD diffractometer with the setup of 0.01°/s and 0.01° per step...Optimum resolution data of X-ray pow- der diffraction for 7-amino desacetoxy cephalospo- ranic acid(7-ADCA) were collected from an X′ Pert Pro MPD diffractometer with the setup of 0.01°/s and 0.01° per step. Indexing to the crystal system and searching space group from the diffraction data were conducted by means of the computational crystal- lography method. The pilot crystal models of 7-ADCA were then refined by Rietveld method to obtain the exact three-dimensional structure. The results show that the crystal structure of 7-ADCA is monoclinic, space group P21 with unit cell dimensions a=13.50 ?, b=6.01 ?, c =5.91 ?, α= γ =90.00°, β =101.96°, Z=2 and V =469.10 ?3. The fraction coordinate of each atom in the unit cell is well located and reported.展开更多
Optimum resolution data of powder X-ray diffraction (PXRD) for Jatrorrhizine (Jat) were collected by an X’ Pert Pro MPD diffractometer with an X’celerator detector under the stepwise scanning condition as 8.255 ms a...Optimum resolution data of powder X-ray diffraction (PXRD) for Jatrorrhizine (Jat) were collected by an X’ Pert Pro MPD diffractometer with an X’celerator detector under the stepwise scanning condition as 8.255 ms and 0.00836° per step, 2θ range of 5°―80° and total scanning period of 8―10 min. Indexing of the crystal system and a search of the space group from the powder X-ray diffraction data were conducted by the computational crystallography method. The pilot crystal models of Jat were globally optimized with Monte Carlo method and then refined with the Rietveld method. In parallel with PXRD test, single crystals of Jat were cultured in an aqueous solution by a slow-decreasing temperature method, then its crystal structure was determined by single crystal X-ray diffraction (SCXRD). Both crystal structures from PXRD and SCXRD are identical. The results show that the crystal structure of Jat belongs to a monoclinic system and the space group P21/c. The parameters of cell dimensions from PXRD are a =7.69, b = 12.55 , c = 20.89 , β = 106.53°, Z = 4, and V = 1933.4 3, meanwhile the parameters from SCXRD are a = 7.72 , b = 12.61 , c =20.99 , β =106.38°, Z =4, and V =1961.3 3.展开更多
文摘Optimum resolution data of X-ray pow- der diffraction for 7-amino desacetoxy cephalospo- ranic acid(7-ADCA) were collected from an X′ Pert Pro MPD diffractometer with the setup of 0.01°/s and 0.01° per step. Indexing to the crystal system and searching space group from the diffraction data were conducted by means of the computational crystal- lography method. The pilot crystal models of 7-ADCA were then refined by Rietveld method to obtain the exact three-dimensional structure. The results show that the crystal structure of 7-ADCA is monoclinic, space group P21 with unit cell dimensions a=13.50 ?, b=6.01 ?, c =5.91 ?, α= γ =90.00°, β =101.96°, Z=2 and V =469.10 ?3. The fraction coordinate of each atom in the unit cell is well located and reported.
文摘Optimum resolution data of powder X-ray diffraction (PXRD) for Jatrorrhizine (Jat) were collected by an X’ Pert Pro MPD diffractometer with an X’celerator detector under the stepwise scanning condition as 8.255 ms and 0.00836° per step, 2θ range of 5°―80° and total scanning period of 8―10 min. Indexing of the crystal system and a search of the space group from the powder X-ray diffraction data were conducted by the computational crystallography method. The pilot crystal models of Jat were globally optimized with Monte Carlo method and then refined with the Rietveld method. In parallel with PXRD test, single crystals of Jat were cultured in an aqueous solution by a slow-decreasing temperature method, then its crystal structure was determined by single crystal X-ray diffraction (SCXRD). Both crystal structures from PXRD and SCXRD are identical. The results show that the crystal structure of Jat belongs to a monoclinic system and the space group P21/c. The parameters of cell dimensions from PXRD are a =7.69, b = 12.55 , c = 20.89 , β = 106.53°, Z = 4, and V = 1933.4 3, meanwhile the parameters from SCXRD are a = 7.72 , b = 12.61 , c =20.99 , β =106.38°, Z =4, and V =1961.3 3.
