Homocyclic Sulfur and Selenium Cations

4/8Sg + 3AsFs S4[AsF6]2 + AsFg Sg + 3AsFs Sg[AsF6]2 + AsFg 

The cyclo-S4 and cations are stabilised in the solid state with respect to their possible dissociation products, i.e. the radical monocations 82 and 84 (or a mixture of 83 and 85 ), respectively, by lattice energy effects. 

For example, the lattice stabilisation enthalpies of cyclo-E4 relative to 2 ions i.e. in E4[AsFg]2 (s) with respect to two molecules of E2[AsFg] (s) are estimated to be 52, 69 and 87 kcalmol for M = 8, 8e, Te, respectively, on the basis of thermochemical calculations (see 8cheme 12.2). In a similar manner, although the gas-phase dissociation 0188 into 83 and 85 is favourable by —32.5kcalmol , solid 8g[AsF6]2 (s) is more stable than the salts of the monocations.  

The radical cation 85 is also formed by the dissociation of in solvents such as fluorosulfuric acid and liquid sulfur dioxide. The second product of this 

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