Asymmetrical diarylmercury compds., e.g. p-MeOC6H4HgC6H4NMe2-p, were produced together with sym. products via a symmetrization process. The asym. products could not be isolated from the reaction mixt. and their existence was indicated through different analyses (m.p., IR, PMR, mass spectra, elemental analysis and DTA). The asym. products are unstable and disproportionate into two sym. compds. at elevated temps., and in org. solvents even at room temp. [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)]
