Spectroscopic studies of N–S–O anions: The reactions of NSO− with elemental sulphur and with S4N4

The reaction of (Me2N)3S+NSO− with sulphur has been investigated by ultraviolet–visible, infrared, Raman, and 14N, 17O, and 33S nuclear magnetic resonance spectroscopies. The red species (λmax 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 "NSO2−" ion have been reinvestigated by infrared, Raman, and 14N nmr spectroscopies, which indicate that the major component of these salts is the NSO− ion. The reaction of (Me2N)3S+NSO− with S4N4 is shown by 14N nmr spectroscopy to produce both S3N3O−, the major product, and S3N3−. Keywords: nitrogen–sulphur–oxygen (N–S–O) anions, 14N NMR spectroscopy.