Ruprecht-Karls-Universität Heidelberg, Physikalisch-Chemisches Institut, Im Neuenheimer Feld 253, 69120 Heidelberg, Germany.
Dalton Trans. 2014 Mar 14;43(10):3958-65. doi: 10.1039/c3dt52989d.
The complexation of Cm(III) with acetate is studied by time resolved laser fluorescence spectroscopy (TRLFS) as a function of ionic strength, ligand concentration, temperature and background electrolyte (NaClO4, NaCl and CaCl2 solution). The speciation of Cm(III) is determined by peak deconvolution of the emission spectra. To obtain the thermodynamic stability constants (log K) for the formation of Cm(Ac)n (n = 1-3), the experimental data are extrapolated to zero ionic strength according to the specific ion interaction theory (SIT). The results show a continuous increase of the stability constants with increasing temperature (20-90 °C). The standard reaction enthalpies and entropies (ΔrH, ΔrS) of the respective reactions are derived from the integrated Van't Hoff equation. The results show that all complexation steps are endothermic and thus entropy driven (ΔrH and ΔrS > 0).
采用时间分辨激光荧光光谱法（TRLFS）研究了 Cm(III)与醋酸根的络合作用，考察了离子强度、配体浓度、温度和背景电解质（高氯酸钠、氯化钠和氯化钙溶液）的影响。通过对发射光谱的峰分解确定了 Cm(III)的形态。为了获得Cm(Ac)n（n=1-3）形成的热力学稳定常数（log K），根据特殊离子相互作用理论（SIT）将实验数据外推至零离子强度。结果表明，随着温度的升高（20-90°C），稳定常数呈连续增加趋势。通过积分范特霍夫方程推导出了各个反应的标准反应焓和熵（ΔrH，ΔrS）。结果表明，所有络合步骤均为吸热，因此是熵驱动的（ΔrH 和 ΔrS > 0）。
