Synthesis of thiadiamidocrown ethers and a thermodynamic study of their complexation with some metal ions using DFT calculations and conductometric method in acetonitrile
作者:Muhammad Ashram、Shehadeh A. Mizyed、Abdel Monem Rawashdeh、Mohammad R. Al-Rbaihat
DOI:10.1080/17415993.2023.2202797
日期:2023.9.3
salts solutions, ⋀, was found to decrease upon addition of crown ethers solutions and tend to level off near the mole ratios [L]T/[M]T of unity. The ΔH° and ΔS° values for the complexation reactions were evaluated from the slopes and intercepts of the van't Hoff plots, respectively. The results show that the stability constants of Pb2+ complexes at 25 °C vary as: 5 > 4 > 2 > 1 while the stability constants
合成了三种新的噻二酰胺冠醚1-3 ,并通过1 H-NMR、13 C-NMR 和质谱进行了表征。化合物1-5与金属阳离子(M n+ )络合的热力学研究;Pb 2+与1、2、4和5;Ag +与1、2和3以及 Hg 2+与2在乙腈中,使用电导技术在 288-308 K 下进行。发现金属盐溶液的摩尔电导率⋀随着添加冠醚溶液而降低,并且趋于在摩尔比[L] T /[M] T附近趋于稳定。络合反应的 ΔH° 和 ΔS° 值分别根据范特霍夫图的斜率和截距进行评估。结果表明,25℃时Pb 2+配合物的稳定常数为: 5 > 4 > 2 > 1 ,Ag +配合物的稳定常数为:3 > 2 >1 . 所有复合物的 ΔG° 值均具有负值,表明复合物自发形成过程。在上述系统上进行的 DFT 理论计算得出的结果支持大多数情况下的实验结果。