Nitrogen NMR of some sulphur diimide anions and calculated (GIAO) nitrogen shielding constants

Sulphur diimide anions of the type [NSN] 2− (1), [RNSN] − (1), [R = t Bu (3), SiMe 3 (4), t Bu 2 P (5)] were prepared with the counter ions [ n Bu 4 N] + or [(Me 2 N) 3 S] + (for 1, 3, 4) and K + (for 5) and studied in solution by 14 N NMR, and for assignment purposes by 15 N NMR (4). The experimentally determined 14 N chemical shifts (δN) were compared with nitrogen shielding constants calculated by the gauge included atomic orbitals (GIAO) technique, and a linear relationship between σ N(calc) and δN was obtained. This correlation serves to support the Z configuration of the anions [RNSN] − , analogous to the isoelectronic N ‐sulphinylamines. On this basis, two 14 N resonance signals reported in the literature with uncertain assignment can be attributed to [HNSN] − (2), and the previously assigned δN values suggest that the anion [HNSNS] − (6) adopts the Z/E configuration.