Group 4 organometallic compounds. Part 8. Preparation and Mössbauer spectra of five- and six-co-ordinate di- and tri-organotin compounds containing mixed phenyl and butyl groups on tin

Abstract

Mössbauer spectroscopic data and preparative details are reported for a range of [Sn^IVBuPh], [Sn^IVBu₂Ph], and [Sn^IVBuPh₂] compounds. The stereochemical preferences of the butyl and phenyl groups in octahedral and trigonal-bipyramidal co-ordination in these mixed-ligand complexes, relative to their symmetrical analogues, have been examined on the additivity model, with comparison between theory and experiment based on our previously reported data on ligand partial quadrupole splittings. For the derivatives of the two triorganotins, trends in centre shift (c.s.) and quadrupole splitting (q.s.) parameters are reported, which are consistent with the additivity model. An approximate inverse correlation has been noted between q.s. and element–oxygen stretching frequency in comparing complexes of [SnBu_xPh_3–x](x= 0, 1, or 2) with PPh₃O and AsPh₃O.