Polymercury cations

TRIMERCURY BIS-[ju-FLUORO-BIS(PENTAFLUOROANTIMONATE-(V))], Hg3(Sb2Fu)2, AND TRIMERCURY BIS [ HEX AF LUOROAR-SENATE(V)],Hg3(AsF6)2 

3Hg + 5SbFs - Hg3(Sb2F11)2 + SbF3 3Hg + 3AsFs - Hg3(AsF6)2 + AsF3 

Antimony pentafluoride (4.94 g, 22.8 mmole) is added, in a good dry box, to side B of the reaction flask using an all-glass syringe. Elemental mercury (2.74 g, 13.7 mmole) is added to side A. The reaction vessel is fitted at E and F with Nupro or similar metal valves, removed from the dry box, and attached to a vacuum line that has been thoroughly flamed before use. Approximately 10 mL of sulfur dioxide is transferred to side B by cooling with liquid N2, and the 

7 Anhydrous sulfur dioxide is dried by storing it over phosphorusCV) oxide before use. 

86(AsF6) - Hg3(AsF6)2 + 2.72Hg Alternate Procedure for Hg2 6(AsF6) 

Due to the hygroscopic nature of (Hg2.86AsFe)a , conductivity measurements have been hampered (158). Recently the four probe ac conductivity has been measured (469) on several randomly orientated single crystals of Hg2.s6AsF6 with the results suggesting a metallic state. At room temperature a high conductivity of 8000 was observed, while at 4.2 K the conductivity in- 

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Exists as the (Hg —Hg) ion. Other polymercury cations, e.g. Hgj (Hg plus AsFj), Hg4 etc., are also known. All positive oxidation state compounds of Hg are readily reduced to the metal, mercury chlorides... 

By comparison with the mercury(I) and mercury(II) ions (Chapter 56.1), the coordination chemistry of (10) and (11) has received little attention. Both ions disproportionate to Hg° and Hg2+ /Hg2+ in media more basic than those from which they can be prepared. However, the existence of (11) (which can be regarded as a complex of (10) with Hg°) and the cation-anion coordination found in solid salts of (10)38 suggest that this ion, at least, might form stable complexes with suitable weak donors. In addition, the formation of as yet incompletely characterized Hg2BrCI04 2SnBr2, which may contain both Hg—Hg and Hg—Sn bonds,42 and the isolation and characterization of [ (np3)Co HgHg Co(np3) ] (1 see Section 11.2) may presage a wider occurrence of catenated heterometallic polymercury species. Slow disproportionation of (11) into (10) and Hg3-X(MF6) occurs even in liquid S02.39 As discussed below, there is evidence for mercury atom transfer between (10) and (11) in liquid S02. 

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