Crystal structure of uranyl chloromethylphosphonate from X-ray powder diffraction data
Crystal structure of uranyl chloromethylphosphonate from X-ray powder diffraction data
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DOI：
10.1016/0022-3697(95)00074-7
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发表时间：
1995-10
影响因子：
4
通讯作者：
D. Poojary;D. Grohol;A. Clearfield
中科院分区：
文献类型：
--
作者：
D. Poojary;D. Grohol;A. Clearfield
利用X-射线粉末衍射法和Rietveld法对一种铀酰基膦酸层状化合物的晶体结构进行了从头算研究。UO_2(O_3PCH_2C_1)属单斜晶系，空间群为P21/c，晶胞参数为a=6.74212(2)，b=7.11507(2)，c=13.1490(1)，Å，β=98.808(1)°，Z=4。P原子的位置由Patterson图得到，碳原子的位置由傅里叶差分图确定。最终一致系数为：RWP=0.117，Rp=0.091，Rf=0.044。直线型铀酰基团与近垂直于铀酰轴的平面上的五个膦酸基配位。膦酸氧的桥联性质导致了化合物的二维层状结构。氯甲基被定向进入层间空间。
The crystal structure of a uranyl phosphonate layer compound was found ab initio by using X-ray powder diffraction data and refined by the Rietveld method. UO2(O3PCH2C1) crystallizes in the monoclinic space group P21/c with a = 6.74212(2), b = 7.11507(2), c = 13.1490(1) A ̊ , β = 98.808(1) ° and Z = 4. The positions of the metal, oxygens and that of the chlorine atoms were obtained from an electron density map computed using 71 unambiguously indexed powder diffraction intensities. The position of the P atom was derived from a Patterson map and that of the carbon atom was located from a Fourier difference map. Final agreement factors are: Rwp= 0.117, Rp= 0.091 and RF= 0.044. The linear uranyl group is coordinated by five oxygens of the phosphonate groups which are located nearly in a plane perpendicular to the uranyl axis. The bridging nature of the phosphonate oxygens leads to a two-dimensional layered structure for the compound. The chloromethyl groups are oriented into the interlayer space.