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A series of six sulfur-selenium mixtures containing 0. 4, 5 , 15, 25, 35, and 45 mol% of selenium were heated in evacuated ampoules at 430°C for 4 h and, keeping the material molten at 135"C, their natural-abundance NMR spectra were recorded. The equilibrium melt in each case was found to contain both heterocyclic Se,,S,-,, species and polymeric material. The most abundant eight-membered selenium sulfide rings were SeS,, which was the main cyclic component in all melts studied in this work, and I ,2-Se2S,, the quantity of which increased with increasing selenium content of the melt. In addition the melts contained smaller amounts of 1,3, 1,4, and 1,5 isomers of Se&, 1,2,3, 1,2,4, and 1,2,5 isomers of Se3Ss, 1,2,3,4, 1,2,3,5. and 1,2,5,6 isomers of Se4S4, 1 ,2,3,4,5-SesS3, I ,2,3,4,5,6-Se,S,, and Se,. The relative distribution of the cyclic products as a function of the selenium content in the melt was virtually identical with that obtained earlier in the CS, solutions of the quenched melts, implying that the extracted quenched melts actually represent the original melt composition as far as the Se,,Sa-,, species are concerned. The resonances due to the polymeric h aterial in the melts could best be interpreted by the statistical random distribution of selenium and sulfur in the polymeric chains, the probability of occurrence of the different fragments being governed by the overall composition of the melt. As the selenium content increases, the relative amount of selenium bound in the polymer seems to increase at the expense of heterocyclic selenium sulfides.Key words: selenium sulfides, sulfur-selenium melt, NMR spectroscopy. naturelle, tout en maintenant les produits ii 1'Ctat fondu i 135°C. Dans chacun des cas, on a trouvC que les produits fondus contiennent des espkces hCtCrocycliques Se,,Sa-, ainsi que des produits polymCriques. Les composCs cycliques les plus abondants sont le cycle sulfur6 du sClCnium comportant huit chainons, SeS,, qui est le composant cyclique principal dans tous les melanges fondus CtudiCs, et le 1 ,2-Se2S6 dont la quantitC augmente avec une majoration de la quantitk de sClCnium dans le produit fondu. On retrouve de plus des quantitiCs plus faibles des isomkres 1,3-, 1,4-et 1 ,5-Se2S6, des isomkres I,2,3-, 1,2,4-et 1,2,5-Se,S,, des isomkres 1,2,3,4-, 1,2,3,5-et 1,2,5,6-Se,S,, du 1 ,2,3,4,5-SesS3, du 1,2,3,4,5,6-Se6S2 et du Se,. La distribution relative des produits cycliques en fonction de la quantitC de sClCnium contenue dans le produit fondu est pratiquement identique avec celle qui a CtC obsewke anterieurement avec des solutions de CS, de produits fondus prkalablement soumis ii une trempe; ce resultat suggkre que, en ce qui a trait aux esp&ces Se,,Sa-,,, les extraits des produits fondus soumis ? i la trempe reprksentent en fait la composition originale du produit fondu. On peut interpreter les rksonances dues ii des matCriaux polymCriques prCsents dans les produits fondus par une distribution statistique du sClCnium et du soufre dans les chaines polymCriques, la probabilitC de rencon...

. Can. J. Chem. 67, 1788 (1989). The reaction of (Me2N)3S+NSO-with sulphur has been investigated by ultraviolet-visible, infrared, Raman, and I4N, 170, and 33S nuclear magnetic resonance spectroscopies. The red species (A,,, 501 nm) formed initially is tentatively identified as SSNSO-. This anion is thermally unstable with respect to the formation of S4N-and sulphur oxyanions. Previously reported salts of the "NS02-" ion have been reinvestigated by infrared, Raman, and ' 4~ nmr spectroscopies, which indicate that the major component of these salts is the NSO-ion. The reaction of (Me2N)$S+NSO-with S4N4 is shown by 1 4~ nInr spectroscopy to produce both S3N3Op, the major product, and S3N3-.Key words: nitrogen-sulphur-oxygen (N-S-0) anions, I4N NMR spectroscopy.TR~STRAM CHIVERS, KENNETH J. SCHMIDT, DEANE D. MCINTYRE et HANS J. VOGEL. Can. J. Chem. 67, 1788 (1989). Faisant a pel aux mCthodes spectroscopiques ultraviolet-visible, infrarouge, Raman et rksonance magnttique nuclCaire du "N, "0 et h , on a Ctudie la rCaction du (Me2N)3S'NSO-avec le soufre. En premiere approximation, on a attribuC la structure SSNSO-aux especes rouges (A,,, de 501 nm) qui se foment initialement. Cet anion est thermiquement stable par rapport i la formation d'ions S4N-et d'oxyanions du soufre. Utilisant les mCthodes spectroscopiques ir, Raman et rmn du I4N, on a rCexaminC la structure de l'ion ((NS02-n dont la formation avait Ct C rapportte antkrieurement; ces rtsultats indiquent que la composante principale de ces sels est l'ion NSO-. En se basant sur la rmn du 1 4~, on dCmontre que la reaction du ( M~~N )~+ N S Oavec le S4N4 conduit ti la formation tant de S3N30-, le produit principal, que de S3N3-. Mots cle's : anions de nitrogene-soufre-oxygkne (N-S-0), spectroscopie RMN du 1 4~.[Traduit par la revue] Introduction Several nitrogen-sulphur-oxygen (N-S-0) anions that contain a sulphoxy group have been characterized. These include the acyclic species NSO-, 1 (1 -3), the ring system S3N30-, 2 (4), and the cage anion S4N50-, 3 (5). Recently we discovered that electrochemically generated solutions of 1 in acetonitrile (ca. 0.3 mM) react with elemental sulphur to give a red anion

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merization of 7 to 5 via PhNH2 elimination seems unlikely since this reaction in independent experiments was found to be very slow and does not yield 5 cleanly.The observed phosphazane products and the product formation order are consistent with those expected in a series that requires successively decreasing PhNH2:PCl3 ratios. Reactant ratios for formation of 8 and 9 are 6:1 (eq 8) and 5.5:1 (eq 9), respectively.6PhNH2 + PC13 -3PhNH3Cl + (PhNH)3P ( 8)The ideal reactant ratio for oligomers 6 and 7 is 5.0:1.0 (eq 3 and 4), and that for the final product 5 is 4.75:1.0 (eq 2).Having observed the complexity of the PCl3-PhNH2 reaction product mixture, how sensitive the product distribution is to reaction conditions, and that the final reaction products 6 (or 7) and 5 have closely similar elemental analytical compositions, we were not surprised that products previously characterized as [(PhNH)PNPh]2 had widely different properties, especially melting points. On the basis of our data, we conclude that material reported to melt at 145-153 °C was mainly [(PhNH)PNPh]2 (7),18-20 that melting at 249-251 °C was [(PhNH)P2(NPh)2]2NPh (5),17,21 and materials with intermediate melting ranges were mixtures of varying amounts of 5, 6, or 7. Only in one case were 3,P NMR data reported.23 Interestingly, a two-resonance pattern