Research Reactor Institute, Kyoto University, 2-1010 Asashiro Nishi, Kumatori, Sennan Osaka 590-0494, Japan.
J Phys Chem A. 2010 Feb 25;114(7):2543-52. doi: 10.1021/jp908642f.
This work reports on the chemical isotope fractionation of Zn(II) by a solvent extraction method with the crown ether dicyclohexano-18-crown-6. The (m)Zn/(64)Zn ratios (m = 66, 67, and 68) were analyzed by multiple-collector inductively coupled plasma mass spectrometry. The relative deviations of the (66)Zn/(64)Zn ratios relative to the unprocessed material (delta(66)Zn) was determined to be -0.51 to -0.32 in the acidity region 1.0-6.0 mol dm(-3) (M) HCl. The acidity dependence of delta(m)Zn was explained by the isotope exchange reactions between Zn(II) species (Zn(2+), ZnCl(+), ZnCl(2), ZnCl(3)(-), and ZnCl(4)(2-)) and the mole fractions of them. The magnitude of delta(m)Zn due to the related Zn(II) species estimated by quantum chemical calculations was in agreement with delta(m)Zn experimentally obtained. Contribution of nuclear field shift to the isotope fractionation was estimated to be less than 10% of delta(m)Zn by quantum chemical calculations.
本工作报道了用冠醚二环己烷-18-冠-6 通过溶剂萃取法分离 Zn(II)的同位素分馏。采用多接收电感耦合等离子体质谱法分析了 (m)Zn/(64)Zn 比值（m = 66、67 和 68）。在酸度为 1.0-6.0 mol dm(-3)（M）HCl 范围内，相对未加工材料的 (66)Zn/(64)Zn 比值的相对偏差（δ(66)Zn）确定为-0.51 至-0.32。δ(m)Zn 的酸度依赖性可以通过 Zn(II)物种（Zn(2+)、ZnCl(+)、ZnCl(2)、ZnCl(3)(-) 和 ZnCl(4)(2-)）与它们的摩尔分数之间的同位素交换反应来解释。通过量子化学计算估算的与相关 Zn(II)物种有关的 δ(m)Zn 的大小与实验获得的 δ(m)Zn 一致。通过量子化学计算估计，核场位移对同位素分馏的贡献小于 δ(m)Zn 的 10%。
