Mechanism of electrophilic substitution at a saturated carbon atom. Part XVII. Mercury(I) as an electrophile towards some transition alkylmetals

Abstract

The penta-aquochromium(III) ion is readily displaced from penta-aquopyridiniomethylchromium(III) ions by direct attack of mercury(I) ion, Hg₂²⁺,aq., on the α-carbon, according to the S_E2 mechanism. The rates of reaction of the 2-, 3-, and 4-pyridiniomethylchromium(III) ions are comparable with those for the corresponding displacements by the mercury(II) ion Hg²⁺,aq. In contrast, the reaction of mercury(I) with some alkyls of iron(II), manganese-(I), and cobalt(III), is negligible compared with that of the small concentration of mercury(II) present in equilibrium with mercury(I).