The tetrafluorophenylmercuric trifluoroacetates, RHgO2CCF3 (R = o-HC6F4, m-HC6F4, p-MeOC6F4, or o-O2NC6F4), and the dimercurated tetrafluorobenzenes o-(CF3CO2Hg)2C6F4 and m-(CF3CO2Hg)2C6F4 have been prepared by mercuration of the appropriate tetrafluorobenzenes with mercuric trifluoroacetate. Reaction of 1,2,3,4-tetrafluorobenzene with mercuric acetate did not give pure monomercurated or dimercurated products, but o-HC6F4HgO2CCH3 and o-(CH3CO2Hg)2C6F4 were obtained analytically pure by treatment of the appropriate trifluoroacetates with acetic acid. The diarylmercurials R2Hg (R = o-HC6F4, m-HC6F4, p-MeOC6F4, or o-O2NC6F4) were prepared by symmetrization of the tetrafluorophenylmercuric trifluoroacetates with iodide or bromide ions in methanol or aqueous methanol. A good yield of (p-MeOC6F4)2Hg, and low yields of crude (m-HC6F4)2Hg and (o-O2NC6F4)2Hg were obtained by mercuration of the corresponding tetrafluorobenzenes under basic conditions, but (o-HC6F4)2Hg could not be obtained by this method. The halogeno derivatives RHgX (R = o-HC6F4 or m-HC6F4), o-(XHg)2C6F4, and m-(XHg)2C6F4 (X = Cl or Br) have been synthesized from the appropriate trifluoroacetates and hydrogen halides and/or by redistribution reactions of suitable mercurials and mercuric halides.