The Radical Ion S₃N₂⁺. Preparation, Electron Spin Resonance Spectrum, and Crystal Structure of Thiodithiazyl Hexafluoroarsenate S₃N₂⁺AsF₆⁻

Abstract

The compound S 3 N 2 + AsF 6 − has been prepared by the reaction of S 4 N 4 with AsF 5 . The crystal structure has been determined from three-dimensional X-ray counter data. Crystals are monoclinic, space group P2 1 /c with a = 8.499(4), b = 8.298(4), c = 11.069(8), β = 94.59(5), V = 778.1 Å 3 , Z = 4, and D c = 2.67 g cm −3 . The structure was solved by Patterson methods and refined to a conventional R factor of 0.028 for 798 independent reflections with I ≥ 3σ(I). The structure consists of discrete AsF 6 − ions and planar cyclic S 3 N 2 + ions. Solutions of S 3 N 2 + AsF 6 − in methylene chloride gave a five-line electron spin resonance spectrum with an intensity ratio of 1:2:3:2:1 showing that the unpaired electron in S 3 N 2 + is coupled to two equivalent nitrogen atoms in full accord with the results of the crystal structure determination.