The reactions of cyclohexane-1,2-bis(4-methyl-3-thiosemicarbazone) (CHMTSC) with MCl2 (M = Co, Ni, Cu or Zn) and Cd(NO3)2 have been shown to produce complexes in which the thiosemicarbazone has been doubly deprotonated [M(CHMTSC − 2H+)] (M = Co, Ni or Ni)}, analogous to those reported earlier with other Schiff base thiosemicarbazones. However, with ZnCl2 and Cd(NO3)2, the complexes isolated are [ZnCl(CHMTSC)]Cl and [Cd(NO3)(CHMTSC)]NO3, containing the protonated forms of the ligand, which have been characterised by X-ray crystallography, as has free CHMTSC. The kinetics of the reactions between CHMTSC and all the various metal salts have been determined by stopped-flow spectrophotometry. In all cases, the reactions are complete on the seconds timescale. The reactions exhibit a first-order dependence on the concentration of metal salt and a first-order dependence on the concentration of CHMTSC. The thermodynamic and kinetic factors influencing the protonation state of the coordinated thiosemicarbazone are discussed.
环己烷-1,2-双(4-甲基-3-
硫脲半缩醛) (CHM
TSC) 与 MCl2 (M = Co, Ni, Cu 或 Zn) 及 Cd(
NO3)2 的反应已证明生成配合物,其中
硫脲半缩醛被双去质子化 [M(CHM
TSC − 2H+)] (M = Co, Ni 或 Ni)},类似先前报道的其他希夫碱
硫脲半缩醛配合物。然而,与 ZnCl2 和 Cd( )2 反应时,所分离出的配合物为 [ZnCl(CHM
TSC)]Cl 和 [Cd( )(CHM
TSC)] ,包含质子化的
配体形式,这些配合物已通过 X 射线晶体学表征,自由 CHM
TSC 亦同。通过停流分光光度法测定了 CHM
TSC 与各种
金属盐反应的动力学。在所有情况下,反应都在几秒钟内完成。反应表现出对
金属盐浓度的一级依赖性,以及对 CHM
TSC 浓度的一级依赖性。讨论了影响配位
硫脲半缩醛质子化状态的热力学和动力学因素。