The interactions of epinephrine ((R)-(−)-3,4-dihydroxy-α-(methylaminomethyl)benzyl alcohol; Eph−) with different toxic cations (methylmercury(II): CH3Hg+; dimethyltin(IV): (CH3)2Sn2+; dioxouranium(VI): UO22+) were studied in NaClaq at different ionic strengths and at T = 298.15 K (T = 310.15 K for (CH3)2Sn2+). The enthalpy changes for the protonation of epinephrine and its complex formation with UO22+ were also determined using isoperibolic titration calorimetry: ΔHHL = −39 ± 1 kJ mol−1, ΔHH2L = −67 ± 1 kJ mol−1 (overall reaction), ΔHML = −26 ± 4 kJ mol−1, and ΔHM2L2(OH)2 = 39 ± 2 kJ mol−1. The results were that UO22+ complexation by Eph− was an entropy-driven process. The dependence on the ionic strength of protonation and the complex formation constants was modeled using the extended Debye–Hückel, specific ion interaction theory (SIT), and Pitzer approaches. The sequestering ability of adrenaline toward the investigated cations was evaluated using the calculation of pL0.5 parameters. The sequestering ability trend resulted in the following: UO22+ >> (CH3)2Sn2+ > CH3Hg+. For example, at I = 0.15 mol dm−3 and pH = 7.4 (pH = 9.5 for CH3Hg+), pL0.5 = 7.68, 5.64, and 2.40 for UO22+, (CH3)2Sn2+, and CH3Hg+, respectively. Here, the pH is with respect to ionic strength in terms of sequestration.

中文翻译：

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了解有毒阳离子存在下肾上腺素的溶液行为：不同实验条件下的热力学研究

肾上腺素 ((R)-(−)-3,4-二羟基-α-(甲基氨基甲基)苯甲醇；Eph−) 与不同有毒阳离子（甲基汞(II)：CH3Hg+；二甲基锡(IV)：(CH3) 的相互作用在不同离子强度和 T = 298.15 K（对于 (CH3)2Sn2+，T = 310.15 K）的 NaLaq 中研究了 2Sn2+；二氧铀 (VI)：UO22+)。肾上腺素质子化及其与 UO22+ 形成络合物的焓变也使用等周滴定量热法测定： ΔHHL = -39 ± 1 kJ mol−1，ΔHH2L = -67 ± 1 kJ mol−1（总反应），ΔHML = −26 ± 4 kJ mol−1，且 ΔHM2L2(OH)2 = 39 ± 2 kJ mol−1。结果表明，Eph− 与 UO22+ 的络合作用是一个熵驱动的过程。使用扩展的 Debye-Hückel、特定离子相互作用理论 (SIT) 和 Pitzer 方法对质子化离子强度和络合物形成常数的依赖性进行了建模。使用 pL0.5 参数的计算来评估肾上腺素对所研究的阳离子的螯合能力。封存能力趋势如下：UO22+>>(CH3)2Sn2+>CH3Hg+。例如，在 I = 0.15 mol dm−3 且 pH = 7.4（CH3Hg+ 的 pH = 9.5）时，UO22+、(CH3)2Sn2+ 和 CH3Hg+ 的 pL0.5 分别 = 7.68、5.64 和 2.40。这里，pH值是相对于螯合的离子强度而言的。