Synthesis, crystal structure and charge distribution of Na7As11O31: An oxygen-deficient layered sodium arsenate
作者:Abderrahmen Guesmi、Massimo Nespolo、Ahmed Driss
DOI:10.1016/j.jssc.2006.04.010
日期:2006.8
A new sodium arsenate with layer structure has been synthesized and its crystal structure solved and refined by single-crystal X-ray diffraction. The crystal is trigonal, space group P3¯m1, a=11.199(3) Å, c=5.411(2) Å, V=587.80(3) Å3, Z=1; the refinement converged to R=0.0282 and wR=0.0751 for 590 reflections with (I)>2sigma(I). The structural model gives the formula Na7As11O32, which would be non-neutral;
合成了一种具有层结构的新型砷酸钠,并通过单晶X射线衍射对其晶体结构进行了解析和精制。晶体是三角形的,空间群为P3’m1 ,a= 11.199(3),,c= 5.411(2),V= 587.80(3)3,Z= 1。对于(I)> 2sigma(I)的590次反射,细化收敛到R = 0.0282和w R = 0.0751。结构模型的公式为Na 7 As 11 O 32,这将是非中立的;此外,结构模型没有通过电荷分布(CD)分析进行验证,这对阳离子的计算电荷给出了不令人满意的协议。CD分析表明O5位置不完全(5/6)占据,这导致每个晶胞缺乏氧原子,分子式为Na 7 As 11 O 31:此新结构模型对应于中性化合物,通过CD分析进行了验证,与非中性对应物相比,O5的位移参数更好。(001)阴离子层是由扭曲的As1和As2的八面体和扭曲的As3和四面体的As3和As3的角和边缘共享建立的,钠阳离子起