论文部分内容阅读
偶氮砷显色剂是一类极重要稀土金属离子显色剂。2-硝基-4-甲基苯胂酸是此类显色剂的一个关键中间体。在粉晶X射线衍射数据指标化结果的基础上,测定了标题物的晶体结构。其晶体学数据是:单斜晶系,空间群为C_(2h)~1—P2/m,a=1.0466(8)nm,b=0.8389(2)nm,c=0.9918(3)nm,β=95.08(3)°,z=4。从Earker截面P(uow)得到了重原子砷的原子分数坐标,在这个基础上,通过几轮重迭峰的分解,由三维电子密度图导出氢原子位置,并用全矩阵最小二乘法对全部304个衍射峰进行了修正,最终残差是:R=9.32%,R_(wp)=10.24%。最后计算了该晶体有关化学键的键长、键角和两面角数据。此外,本文还探讨了稀土金属离子与该显色剂显色反应机理,并预报了凡金属离子半径在0.09～0.11nm范围内,均可应用该显色剂络合显色。
Azo arsenic developer is a very important class of rare earth metal ion developer. 2-Nitro-4-methylbenzenesulfonic acid is a key intermediate for such developers. Based on the results of the indexing of the powder X-ray diffraction data, the crystal structure of the title material was determined. The crystallographic data are as follows: monoclinic system with space group C 2h ~ 1-P2 / m, a = 1.0466 (8) nm, b = 0.8389 = 95.08 (3) °, z = 4. From the Earker cross section P (uow), we get the atomic fractional coordinates of heavy atom arsenic. On this basis, through the decomposition of several overlapping peaks, the position of hydrogen atom is deduced from the three dimensional electron density map, and the full 304 The diffraction peaks were corrected. The final residuals were: R = 9.32%, R_ (wp) = 10.24%. Finally, we calculated the bond length, bond angle and dihedral angle of the chemical bond of the crystal. In addition, the mechanism of color reaction between rare earth metal ions and the chromogenic reagent is also discussed in this paper. The colorimetric complex coloration can be predicted when the radius of metal ions is in the range of 0.09 ~ 0.11 nm.