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 Sn-119 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-Trip(2) (X = Cl, Cr(eta (5)-C5H5)(CO)(3), t-Bu, Sn(Me)(2)C6H3-2,6-Trip(2); Trip = C6H2-2,4,6-i-Pr-3). 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 Sn-119 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-Trip(2)H(3)C(6)Sn-Sn(Me)(2)C6H3-2,6-Trip(2) 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.