Bis(n-alkanethiolato)mercury(II) compounds, Hg(SCnH2n+1)2 (n=1 to 10, 12):: Preparation methods, vibrational spectra, GC/MS investigations, and exchange reactions with diorganyl disulfides

Several preparative routes to bis(n-alkanethiolato)mercury(II) compounds of the general composition Hg(SCnH2n+l)(2) for n = 1-10, 12 (compounds 1-11, respectively) are presented, including the reaction of mercury(II) iodide with n-alkanethiols and triethylamine as an auxiliary base, as well as the reaction of mercury(II) chloride with trimethylsilyl methyl sulfide as an example for this particular type of exchange reaction using trimethylsilyl sulfides as thiolate transferring reagents. With respect to the possibility of mobilizing these compounds into the environment under special natural surroundings, as for example found in some natural gas reservoirs, the reactivity of the title compounds toward excess di-n-alkyl disulfides leading to the exchange of the thiolate functional groups of both the mercury compounds and the disulfides is investigated. Equilibration reactions of specifically stoichiometric amounts of Hg(SC3H7)(2) (3) and C7H15SSC7H15, as well as Hg(SC7H15)(2) (7) and C3H7SSC3H7 are investigated in more detail using the coupling of gas chromatography and mass spectrometry (GC/MS). The FT-LR and FT-Raman spectroscopic data of the solid title compounds are given and discussed. Assignments of v(s)(Hg-S) and v(as)(Hg-S) stretchings, as well as delta (C-S-Hg) and delta (S-Hg-S) bendings are reported and discussed in comparison to literature data. The spectroscopic data suggest mercury to be two-coordinated in all studied compounds with the exception of Hg(SC4H9)(2) (4). This particular compound obviously contains a four-coordinated central mercury atom. The title compounds were analyzed by means of GC/MS, which indicated that the compounds (i) decompose at elevated temperatures, mainly to form mercury and the corresponding disulfide, and (ii) are monomer in the gas phase.