119sn NMR studies on the complexation of tin (II) halides with various donor solvents

The 119Sn chemical shift of SnX2 (X = F, Cl, Br, I) over a range of solute concentrations in HMPA, DMSO, DMF and glyme are reported. Equilibrium constants for the Complexation of SnX2 with some of these solvents are calculated by assuming a two-site exchange model. Relatively poor precision of calculated equilibrium constants was interpreted as evidence that a two-site exchange model does not provide a satisfactory description of the system. Various factors, such as self-association, ionization and/or temperature dependent shift, are believed to contribute to the scatter of data points which results in inconsistent K values.