The Mössbauer spectra, structure, and bonding of some hexaco-ordinate compounds of tin(IV)

Abstract

The Mössbauer spectra of a large number of hexaco-ordinate tin(IV) compounds have been investigated. No quadrupole interaction is observed even when the six atoms bonded to tin are not all the same, provided that all six have non-bonding pπ electrons. When some of the attached groups have no such pπ electrons (e.g., methyl) then substantial quadrupole splitting is observed. Isomer shifts show the expected trend with electronegativity of the halogen but are somewhat insensitive to the nature of the chelating ligand. The results have been used to draw structural conclusions about several compounds whose detailed structures have not previously been established unambiguously. Among these are the adducts of the tin(IV) halides with 8-hydroxyquinoline, with [Ph₂P(O)]₂NH, and with dinitrogen tetroxide.