Sulfur rings, energy levels

Meyer and Spitzer (52) have calculated the electronic properties of rings and chains of sulfur atoms. An EH procedure was employed with parameters chosen to fit the energy levels of S8. For S4 it was found that the tetrahedron was only weakly stable, with branched chains and zigzag chains more stable. The calculations predict that above S5 the gas-phase species are cyclic. In addition to these geometry effects, a long-wavelength shift was observed for light absorption by the chains. 

Figure 11. Energy leveb of (a) sulfur rings, (b) sulfur chains, (c) isomers and conformers of Sj, and (d) sulfanes. AU energy levels were computed with an...

The +C(SH)3 cation and the radical dication derived from it have been the subject of high-level calculations.67 The ability of two adjacent sulfur atoms to stabilize cations, anions, and radicals makes these species usefiil for relating bond-breaking and electron-transfer energies.68,69 Electrophilicity parameters for the dithiocarbenium ions (27) have been worked out,70 and the stabilities of the cations (28), (29) and (30) have been estimated using PM3 calculations.71 Cation (31) can be captured by solvent or azide ion, or it may ring close to (32), which subsequently alkylates another (31) cation as shown.72... 

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