PhHgOAc is converted into Ph2Hg via a symmetrization process, in the absence of an auxiliary ligand, at 6.5≥pH\textgreater4.0. Arylmercuric salts, in which the arom. rings contain more than 1 electron donating group, symmetrize in the absence of an auxiliary ligand at a basic pH. Both processes proceed in water or in mixts. of org. solvents and water. The factors influencing the symmetrization at different pH values are discussed. [on SciFinder(R)]

The mechanism for the symmetrization of arylmercuric salts in the presence of chelating agents includes 3 main steps: (i) dissocn. of the arylmercuric salt; (ii) formation of a reactive complex between the ionized arylmercuric salt and the chelating agent; (iii) an electrophilic substitution at a C-Hg bond via a 2-electron, 3-center bond type transition state. The effect of chelating agents on the reactions of PhHgOAc with piperidine, BuNH2, or CNS- to give Ph2Hg and of m-MeC6H4HgOAc with tetra-Na ethylenediaminetetraacetate to give (m-MeC6H4)2Hg was discussed. [on SciFinder(R)]