Solid-state and high-resolution liquid ¹¹⁹Sn NMR spectroscopy of some monomeric, two-coordinate low-valent tin compounds: Very large chemical shift anisotropies

High-resolution liquid- and solid-state ¹¹⁹Sn NMR spectroscopy was used to study the bonding environment in the series of monomeric, two-coordinate Sn(II) compounds of formula Sn(X)C₆H₃-2,6-Trip₂ (X = Cl, Cr(η⁵-C₅H₅)(CO)₃, t-Bu, Sn(Me)₂C₆H₃-2,6-Trip₂; Trip = C₆H₂-2,4,6-i-Pr₃). The trends in the principal components of the chemical shift tensor extracted from the solid-state NMR data were consistent with the structures determined by X-ray crystallography. Furthermore, the spectra for the first three compounds displayed the largest ¹¹⁹Sn NMR chemical shift anisotropies (up to 3798 ppm) of any tin compound for which data are currently available. Relaxation time based calculations for the dimetallic compound 2,6-Trip₂H₃C₆ S̈n-Sn(Me)₂C₆H₃ -2,6-Trip₂ suggests that the chemical shift anisotropy for the two-coordinate tin center may be as much as ca. 7098 ppm, which is as broad as the 1 MHz bandwidth of the NMR spectrometer.