Mössbauer Spectra, Bonding, and Structure In Sn(IV) Acetylacetonates

Abstract

119Sn Mössbauer spectra have been recorded for sixteen acetylacetonates of the type R2–xClxSnL2 (R=Me, Ph; L=anions of acetylacetone or substituted acetylacetone) and Cl4SnHL. The quadrupole splittings have been used to assign stereochemistry for most of these compounds. The good correlation between quadrupole splitting and center shift for the dimethyl analogues shows that there is no appreciable Sn 5s character in the Sn—L bonds. The correlation between [Formula: see text] and center shift for the dimethyl compounds is consistent with the above interpretation, and indicates that changes in [Ψ(0)5s]2 are dominant in determining both the center shift and J values for these compounds. The Mössbauer parameters for the compounds containing a neutral ligand show that the bonding properties of HL are very similar to those of L.The dimethyl compounds all show a pronounced Goldanskii–Karyagin asymmetry in their spectra. The direction of this asymmetry is shown to be consistent with a positive quadrupole splitting for all the dimethyl compounds.