The EPZ015666 of mercury with AsF5 using SO2 as a solvent yields various homopolyatomic cations of mercury stabilized by [AsF6]− anions  and . The formal oxidation state of mercury in those compounds is lower than +2 which is otherwise typical of Group 12 elements. The large excess of AsF5 yields Hg22+ salt, meanwhile with the decreasing amount of the oxidant, Hg32+, Hg42+ and Hg2.86+ compounds can be prepared ,  and . Later it was discovered that the reaction of mercury with various Hg(II) hexafluorides, Hg(MF6)2 (M=As, Sb, Nb, Ta), is a more useful and more general method of preparing Hg32+ and Hg42+ salts  and . With the exception of Hg2(AsF6)2, the crystal structures of Hg3(AsF6)2, Hg4(AsF6)2 and Hg2.86(AsF6) are known . On the other hand, the crystal structure information about Hg(MF6)2 (M=M5+) ,  and  are limited only to Hg(AuF6)2 . The Hg(AsF6)2, prepared by reaction between HgF2 and AsF5 in anhydrous HF at ambient temperature, has been characterized only by vibrational spectroscopy . The study of its thermal decomposition showed that at 65–95 °C orders first decomposes to HgFAsF6 and later with increased temperature to HgF2 .