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

Abstract

The compound S₃N₂⁺AsF₆⁻ has been prepared by the reaction of S₄N₄ with AsF₅. The crystal structure has been determined from three-dimensional X-ray counter data. Crystals are monoclinic, space group P2₁/c with a = 8.499(4), b = 8.298(4), c = 11.069(8), β = 94.59(5), V = 778.1 ų, 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 AsF₆⁻ ions and planar cyclic S₃N₂⁺ ions. Solutions of S₃N₂⁺AsF₆⁻ 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 S₃N₂⁺ is coupled to two equivalent nitrogen atoms in full accord with the results of the crystal structure determination.