Ozaki T, Arisaka M, Kimura T, Francis A J, Yoshida Z
Advanced Science Research Center, Japan Atomic Energy Research Institute, Tokai-mura, Ibaraki 310-1195, Japan.
Anal Bioanal Chem. 2002 Nov;374(6):1101-4. doi: 10.1007/s00216-002-1587-1. Epub 2002 Oct 19.
The number of water molecules in the inner-sphere (N(H2O)) was determined for Eu(III) and the strength of ligand field (R(E/M)) was evaluated for a variety of coordination environments from the luminescence lifetime and the relative intensity at 615 nm and at 592 nm, by time-resolved laser-induced fluorescence spectroscopy. When R(E/M) and deltaN(H2O) for Eu(III) with a known coordination environment were plotted clear regularity was apparent between the location of the R(E/M)-deltaN(H2O) plot and the coordination environment of Eu(III). Here, deltaN(H2O) was calculated by use of the equation, deltaN(H2O)=9-N(H2O). Unknown coordination environments of Eu(III) can, in turn, be characterized, including both the inner- and the outer-sphere, simply by plotting R(E/M) and deltaN(H2O) for Eu(III) on the diagram. This empirical method is effective for prediction of the coordination environment of hydrated and complexed Eu(III) in solutions and that of the adsorbed Eu(III) on ion-exchange resins and by microorganisms.
通过时间分辨激光诱导荧光光谱法，根据发光寿命以及615纳米和592纳米处的相对强度，测定了铕（III）内球中的水分子数（N(H₂O)），并评估了各种配位环境下的配体场强度（R(E/M)）。当绘制具有已知配位环境的铕（III）的R(E/M)和ΔN(H₂O)时，R(E/M)-ΔN(H₂O)图的位置与铕（III）的配位环境之间呈现出明显的规律性。这里，ΔN(H₂O)通过公式ΔN(H₂O)=9-N(H₂O)计算得出。反过来，仅通过在图上绘制铕（III）的R(E/M)和ΔN(H₂O)，就可以表征铕（III）未知的配位环境，包括内球和外球。这种经验方法对于预测溶液中水合和络合的铕（III）、离子交换树脂上吸附的铕（III）以及微生物吸附的铕（III）的配位环境是有效的。
