Kinetics and mechanism of the substitution reactions of some bifunctional palladium(II) complexes with different nitrogen-donor heterocycles
作者:Milica Kosović、Željko Jaćimović、Živadin D. Bugarčić、Biljana V. Petrović
DOI:10.1007/s11243-015-0008-1
日期:2016.3
Substitution reactions of three Pd(II) complexes, [Pd(cbdca)Cl2]2− (cbdca = cyclobutane-1,1-dicarboxylato), [Pd(ox)Cl2]2− (ox = oxalato) and [Pd(mal)Cl2]2− (mal = malonato), with different five- and six-membered N-heterocycles, such as pyrazole, 3-amino-4-iodo-pyrazole (pzI), 5-amino-4-bromo-3-methyl-pyrazole (pzBr), 1,2,4-triazole, pyrazine, imidazole, pyridazine and pyrimidine, were investigated
三种 Pd(II) 配合物的取代反应,[Pd(cbdca)Cl2]2− (cbdca = cyclobutane-1,1-dicarboxylato), [Pd(ox)Cl2]2− (ox = oxalato) 和 [Pd(mal) )Cl2]2− (mal = 丙二酸),具有不同的五元和六元 N-杂环,例如吡唑、3-氨基-4-碘-吡唑 (pzI)、5-氨基-4-溴-3-甲基吡唑 (pzBr)、1,2,4-三唑、吡嗪、咪唑、哒嗪和嘧啶,在含有 20 mM NaCl 的 0.10 M NaClO4 水溶液中使用可变温度停流分光光度法进行研究。这些复合物的取代发生在两个连续的可逆步骤中,它们的反应性依次降低 [Pd(cbdca)Cl2]2->[Pd(mal)Cl2]2->[Pd(ox)Cl2]2-。五元杂环中反应性最强的亲核试剂是咪唑,而哒嗪是六元杂环中反应性最强的。确定所有反应的活化参数,活化熵的负值