| Abstract
| - In the solid state, the thiazylamide anion Me3CNSN- of the salt TAS+Me3CNSN- (1a) adopts the electronically favored Z-configuration, while the Me3SiNSN- anion of TAS+Me3SiNSN- (1b) unexpectedly adopts the E-configuration. This paper examines if weak anion−cation interactions as well as electronic effects are responsible for this unexpected configuration.
- TAS+ salts (TAS = (Me2N)3S) of the sulfur diimide anions Me3XNSN- (X = C (1a), Si (1b)) were prepared bySi−N bond cleavage from the corresponding sulfur diimides Me3XNSNSiMe3 and TAS-fluoride ((Me2N)3S+Me3SiF2-)and characterized by X-ray crystallography and multinuclear NMR spectroscopy. According to the experimentallydetermined bond lengths and theoretical calculations, the Me3XNSN- anions are best described as thiazylamidesMe3X−N−S⋮N rather than sulfur diimides Me3X−NSN. In agreement with the calculated and experimentallydetermined structures of the isoelectronic thionylimides RNSO, 1a adopts the Z-configuration, which is electronicallyfavored due to anomeric effects. The electronically disfavored E-configuration of 1b in the solid state can beexplained by weak anion−cation interaction.
|
