Polymeric thiolate complexes in solution. Stability constants of the zinc(II) complexes of 1-methyl-4-mercaptopiperidine
The equilibrium reaction between ZnII and 1-methyl-4-mercaptopiperidine has been studied by e.m.f. measurements with a glass electrode at 25 °C in a 3 mol dm–3(sodium) perchlorate medium [+10%(v/v) CH3OH]. Conclusions drawn from graphical methods based on the ‘core + links’ hypothesis are in agreement with the results obtained from the numerical treatment. The e.m.f. data obtained in the range 4 < –log[H+] < 9 can be explained by assuming the existence of the following species: [Zn3(HA)6]6+(log ψ3, 6= 39.71 ± 0.01), [Zn5(HA)12]10+(log ψ5,12= 79.87 ± 0.01), and [Zn2(HA)6]4+(log ψ2,6= 35.26 ± 0.02) where HA is the uncharged ligand. A mechanism for the formation of these species and their possible geometries are suggested.