Spaltung von S₄N₄ zu S₂N₂ bei Raumtemperatur: Darstellung und Struktur von S₂N₂ • 2AlBr₃ / Cleavage of S₄N₄ to S₂N₂ at Room Tem perature: Preparation and Structure of S₂N₂ • 2AlBr₃

Abstract

The compound S 2 N 2 • 2AlBr 3 has been prepared by reaction of S 4 N 4 with AlBr 3 in 1,2-dibromoethane at room temperature. Its crystal and molecular structure have been determined by X-ray diffraction; R = 0.068. Crystal data: monoclinic, P 2 1 /n, a = 9.594(5), b = 9.975(4), c = 7.528(4) Å , β = 111.36(5)°. The S 2 N 2 ring of the centrosymmetrical complex is bonded via its nitrogen atoms to two AlBr 3 units thus completing coordination tetrahedra around the Al atoms. Bond distances and angles within the S 2 N 2 ring are d(S-N) = 1.629(13) and 1.651(13) Å, ∢ (S-N-S) = 95.8, and ∢ (N-S-N) - 84.2°. Whereas the S-N bond lengths agree closely with those of free S 2 N 2 , the angle at N is enlarged by ca. 5° and the angle at S is decreased by ca. 5°. The sulfur atoms form two close S···Br contacts of length 3.149 (intramolecular) and 3.193 (intermolecular) Å , respectively. The intermolecular attractive nonbonded S···Br interactions tie the complexes together in a way that leads to infinite chains which run parallel to the crystallographic z axis