REACTIONS OF S4N4 AND S3N3CL3 WITH SELENIUM CHLORIDES - THE PREPARATIONS AND CRYSTAL-STRUCTURES OF SES2N2CL2, (S5N5)(SECL5), AND THE DISORDERED MATERIALS (SEXS3-XN2CL)(SBCL6)

The reactions of S4N4 with SeCl4 and of S3N3Cl3 with Se2Cl2 in 1:1 molar ratios in SO2 as solvent give the crystalline compounds (S5N5)(SeCl5) (1) and SeS2N2Cl2 (2), respectively. Compound 2 is also obtained by the reaction of 2 mol of S3N3Cl3 with 3 mol of Se2Cl2 in acetonitrile. Orange crystals of 1 are orthorhombic, space group Prima, with a = 11.252 (2) Å, b = 12.075 (2) Å, c = 9.987 (2) Å, V = 1356.4 (4) Å3, and Dc = 2.38 g cm−3 for Z = 4. Red-orange crystals of 2 are monoclinic, space group P21/c, with a = 10.447 (2) Å, b = 9.259 (2) Å, c = 13.529 (3) Å, β = 105.93 (2)°, V= 1258.4 (4) Å3, and Dc = 2.55 g cm−3 for Z = 4 (ion pair + molecule). In 1 the pentathiazyl S5N5 + cation and square-pyramidal SeCl5 − anion have crystallographic mirror symmetry and are strongly associated by a short Se-N contact of length 2.794 (5) Å in the sixth coordination site around the selenium. Compound 2 surprisingly contains both a neutral molecule SeS2N2Cl2 and an intimate ion pair SeS2N2Cl+Cl− in the same lattice. In the neutral molecule the Se atom has an AX4E disphenoidal primary geometry and an overall AX4Y′2E distorted-octahedral geometry while the geometry of the Se atom in the ion pair is AX3Y3E distorted octahedral. The Se⋯Cl secondary contacts in this structure are described and discussed. The 15N NMR spectrum of 2 in 100% sulfuric acid has a pair of doublets at δ = −51.7 and -137.8 ppm with. {formula-omited} while the 77Se NMR spectra of natural-abundance and 15N-enriched SeS2N2Cl2 have a singlet and a doublet with {formula-omited}, respectively, at δ = 326.0 ppm consistent with the formation of the SeS2N2Cl+ cation in solution. Further reactions of S4N4 with Se2Cl2/SbCl5 or SeCl4/SbCl5 mixtures in SO2 gave disordered compounds with the general formula SexS3−xN2Cl+SbCl6 − (x = 0–3). Some crystallographic data for these compounds are reported. © 1990, American Chemical Society. All rights reserved.